ML101940276

Nuclear Condition Report for Tritium in Groundwater

ML101940276
Person / Time
Site:	Harris
Issue date:	12/02/2008
From:	- No Known Affiliation
To:	Office of Information Services
References
FOIA/PA-2010-0209
Download: ML101940276 (14)

Text

3 Page Printed: 04/29/09 ACTION REQUEST 00309035 Type  : NCR Orig Date: 12/02/08 07:38 Discovery Date:

Subject  : WATER IN CISTERN BOX AIR RELIEF VLVE#1 COOLING TOWER BLOWDOW Description THE CISTERN BOX SURROUNDING AIR RELIEF VALVE #10F COOLING TOWER BLOWDOWN LINE WAS INSPECTED ON 12/1/08 AT 1300. THE BOX HAD APPROXIMATELY 150 GALLONS OF STANDING WATER. TWO WEEKS PREVIOUS, 11/18/08 THE CONTAINMENT BOX WAS PUMPED OUT AND 150-200 GALLONS OF WATER WAS REMOVED. A SAMPLE WAS PULLED FOR ANALYSIS. THE WATER WAS COUNTED TO HNP LOWER LIMIT OF DETECTION AND WAS FOUND TO HAVE <1850 PCI/L OF TRITIUM. COOLING TOWER BLOWDOWN DISCHARGE IS AROUND 3500 PCI/L, THEREFORE THE WATER DOES NOT HAVE THE CHARACTERISTICS OF PLANT EFFLUENT. THE SAMPLE WAS SENT TO THE HEEC TO BE ANALYZED TO THE ENVIRONMENTAL LOWER LIMIT FROM TRITIUM OF 250 PCI/L.

Priority  : 2 Report To  : Status: APPROVED 12/04/08 Due Date  : 12/03/09 Event Date Originator  : BAXTEH Originator Group:

Facility  : HNP Department I75 1: Organization:

owed To  : Owed To Group  : CHUEVAL Owed To Fac: HNP Department  : Discipline AR Status History Updated Date Updated By AR Status AR Due Date 12/02/08 BAXTEH INPROG 12/02/08 BAXTEH H/APPR 12/04/08 FURRJA 12/03/09 12/04/08 FURRJA PRE-APRV 12/04/08 FURRJA APPROVED A

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ATTACHMENT 3 Sheet 1 of 2 ADVERSE CONDITION INVESTIGATION FORM Form CAP-NGGC-0200-3-18 Action Request Number: 309035 Investigator: Heather Baxter

1. Adverse Condition Description The cistern box surrounding air relief valve #1 of cooling tower blowdown line was inspected on 12/1/08 at 1300. The box had approximately 150 gallons of standing water. Two weeks previous, 11/18/08 the containment box was pumped out and 150-200 gallons of water was removed. A sample was pulled for analysis. The water was counted to HNP lower limit of detection and was found to have <1850 pCi/L of tritium. Cooling Tower Blowdown discharge is around 3500 pCi/L, therefore the water does not have the characteristics of plant effluent. The sample was analyzed by the HEEC and found to contain 735 pCi/L

+/- 155 pCi/L. This is less than the 20,000 pCi/L reporting criteria, therefore the sample is not reportable.

2. Investigation Summary

" What Should Be:

o The Cooling Tower Blowdown Air Relief Valve cistern boxes should be devoid of standing water.

o The groundwater along the Cooling Tower Blowdown line cannot have detectible tritium.

• What Is:

o The cistern box surrounding the air relief valve #1 has historically filled with groundwater. The water level inside the box rises and falls depending upon weather conditions.

o Several repeat samples of the groundwater in the cistern have shown about 800 pCi/L +/- 155 pCi/L of tritium.

• How it happened:

o On 12/16/08 the cistern box was pumped out a second time and 225 gallons of water was removed. During the pump out, groundwater flowed into the cistern via a drain pipe hole located on the floor of the cistern.

o A sample of the water from the drain pipe contained 850 pCi/L +/- 155 pCi/L of tritium.

• The inappropriate act or equipment malfunction.

o The cistern box drain is designed to drain water from the cistern to the surrounding ground to prevent standing water from accumulating around the air relief valve stem. The hydraulic pressure from the surrounding water table causes groundwater to backflow into the cistern.

o An unknown source of tritium is contaminating the groundwater surrounding the air relief valve

1. 1 cistern box.

• Why happened.

o The Cooling Tower Blowdown line is a 4 foot fiberglass line that is buried underground. It travels from the discharge weir at the base of the Cooling Tower to the discharge point near Harris Lake Spillway. In order to prevent air binding of the line, a series of air relief valves and manholes are placed along the length of the pipe. During plant construction, the pipe was buried several feet underground. The air relief valves were placed inside of large underground cisterns to provide easy access.

According to plant construction diagrams, the Cooling .Tower Blowdown pipe was placed upon a bed of gravel and backfilled with soil. At the bottom of each cistern was a small drain, which drains to the surrounding gravel. During the pump out on 12/16/08 it was observed that water was flowing into the cistern from the drain hole at a rate of about 0.5 L/min.

o As part of the site's Radiological Environmental Monitoring Program (REMP) the HNP Environmental Groundwater Monitoring Program utilizes on-site deep wells to. monitor the tritium concentration of the groundwater. The typical lower level of detection for tritium in groundwater samples is 250 pCi/L. Historically the site's monitoring wells have all been less than detectible

(<LLD) for tritium. The water inside of the cistern was sampled and analyzed at the environmental lower limit of detection. The table below shows the results:

Tritium (pCi/L)

(+/-155 pCi/L) 9/15/08 747 10/15/08 878 12/1/08 735 12/16/08 850 Even after the cistern is pumped out or rainfall events, the concentration of tritium within the cistern is within the error associated with the measurement. Therefore, the groundwater surrounding the cistern is contaminated with 800 pCi/L of tritium.

The pipe carries plant liquid releases to Harris Lake for discharge. Because of the reuse of Harris Lake, the concentration of tritium in the blowdown effluent is approximately 4000-5000 pCi/L. This concentration varies due to release tanks, concentration of lake tritium, and rainfall.

In addition, the concentration of Harris Lake itself ranges from 3000 - 9000 pCi/L. At this point it is difficult to say where the tritium in the groundwater is coming from. It is possible that the tritium in the lake is impacting the groundwater surrounding the Cooling Tower Blowdown line or the Cooling Tower Blowdown line has a leak which is releasing blowdown effluent into the groundwater. Further investigation will be required to determine the source of the tritium in the groundwater.

An action plan will need to be developed to identify the source of the tritium in the groundwater, as well as, the remediation protocol to prevent migration of licensed material off-site and to minimize decommissioning impacts.

DESCRIPTION CAUSE COD ORG CORRECTIVE ASSIGNMENT ASSIGNEE/ DUE OR E ACTION TYPE CONCURREN COMPLETIO CE N DATE**

ADVERSE 800 pCi/L of Pump out the water CORR Larry Garner Complete CONDITION tritium was N/A NIA N/A in the cistern box discovered in and dispose of the the Cooling water appropriately Tower Air Relief cistern Develop and CORR Heather 4/15/09 implement Action Baxter Plan for tritium source I/A Detectible (Apparent) J7U N/A See corrective NA NA NA concentration of The Cooling Tower action above for tritium found in Blowdown line may adverse condition water be leaking blowdown effluent OTHER Document in the ENHN Heather 6/1/09 N/A N/A N/A NIA 2008 ARERR Baxter report the groundwater cister results J:\Shared\Cause Codes\CAP Cause Codes.doc

Page 10 Printed: 04/29/09 ACTION REQUEST 00309035 ASSIGNMENT NUMBER05 SUB Type  : CORR Due Date  : 07/16/09 Status  : NTFY/ASG Reschedule  : 1 Pri Resp Group: ERCCSUPT Assigned To : H BAXTER Sec Resp Group:

Subject  : CORR-DEVELOP AND IMPLEMENT ACTION PLAN FOR TRITIUM SOURC Aff Facility: HNP Unit  : System UCR Schedule Ref Organization: Department  : 175 Discipline Est Manhrs  : Est Comp Date Assignment Status History Updated Date Updated By Assgn Status Assgn Due Date 12/02/08 BAXTEH INPROG 12/31/08 GRUBBT 04/15/09 12/31/08 GRUBBT NTFY/PRI 12/31/08 CATTCH ACC/PRI 12/31/08 CATTCH NTFY/ASG 04/15/09 FURRJA 07/16/09 DEVELOP AND IMPLEMENT ACTION PLAN FOR TRITIUM SOURCE Assignment Attribute Value Reqd Date BENEFIT REALIZED N Name Assignment Attribute Value Reqd Date 1 UNIT/SECT EVALUATR N Name Assignment Attribute Value Reqd Date 1A COMMITTED N Name :

Assignment Attribute Value Reqd Date lB CHANGE BASIS N Name First extension approved by Supervisor and Licensing/PERAS if NRC committed Additional extensions approved by Unit Manager/Superintendent and Licensing/PERAS if committed Justification should include the following:

Why the assignment is being extended; to allow implementation of action plan The new due date: 7/16/09 Why the new due date is acceptable from a nuclear safety and risk perspective: No radiological concern since we are dealing with Cooling Tower blow down line.

Concurrence received from Chris Burton via Mike Robinson on 4/15/09.

Page  : ii Printed: 04/29/09 ACTION REQUEST 00309035 Assignment Attribute Value Reqd Date 2 MISCELLANEOUS N Name Assignment Attribute Value Reqd Date 2A COMMENTS N Name Assignment Attribute Value Reqd Date 2B COMMENTS N Name Assignment Attribute Value Reqd Date 2C COMMENTS N Name :

Assignment Attribute Value Reqd Date 2D COMMENTS N Name :

Assignment Attribute Value Reqd Date 2E COMMENTS N Name Assignment Attribute Value Reqd Date 3A LTCA APPROVAL N Name Assignment Attribute Value Reqd Date 3B LTCA CONCURRENCE N Name :

COMPLETION NOTES CAUSE/ACTION ASSIGNMENT COMPLETION APPROVAL Route List: 001 Route List Initiator:

Alert Send Send Action Action PASSPORT Fac Group/Type Last Name Date Time Taken Date/Time HNP ERCCSUPT A HNP CHUEVAL A

Develop and implement Action Plan for tritium source HNP Action Plan for GroundwaterProtectionProgram Rev 1 (1/7/09)

Developer: Heather Baxter, Don Edwards Responsible Supervisor: Mike Robinson Date Initiated: 1/5/2009 AR Number: 309035 Section 1 -Define Problem and. Expected Results In accordance with the industry's Groundwater Protection Initiative, Harris Nuclear Plant is required to develop and implement a groundwater protection program to assure timely and effective management of situations involving inadvertent releases of licensed material to the groundwater.

This action plan will address management, remediation and decommissioning impacts of tritium detected along the Cooling Tower Blowdown Line and the addition of new monitoring wells.

Section 2 - Current Facts and Assumptions

• Facts:

The water that is flooding the cistern that surrounds the Air Relief Valve #1 of the Cooling Tower Blowdown line contains 800 pCi/L of tritium. Both Harris Lake and the Cooling Tower Blowdown typically contains about 6000 pCi/L tritium. As part of the site's Radiological Environmental Monitoring Program the HNP Environmental Groundwater Monitoring Program utilizes on-site deep wells to monitor the tritium concentration of the groundwater. The typical lower level of detection for tritium in the groundwater samples is 250 pCi/L. Historically the site's monitoring wells have shown less than detectible (<250 pCi/L) of tritium. Therefore, the tritium concentration in the groundwater is not naturally occurring.

There are currently no monitoring wells in the vicinity of the Cooling Tower Blowdown line; therefore the hydrogeological conditions of the site have not been evaluated.

Assumptions:

Since the source of the tritium in the groundwater surrounding the Cooling Tower Blowdown line is not naturally occurring, it is assumed that the groundwater tritium is either due to a Cooling Tower Blowdown Line leak or Harris Lake influence.

Section 3 - Define Needed Resources Chemistry -

1. Manage the Groundwater Protection Program to ensure compliance with all rules and regulations

2. Analyze the groundwater samples for tritium and gamma emitters

3. Make recommendations for remediation

4. Document actions associated with this action plan in the site decommissioning 50.75(g) file.

5. Analyze soil samples for gamma emitters

6. If blowdown line is found leaking, estimate the leak rate to determine if a leak of licensed material exceeds the NEI 07-07 volumetric criteria for licensed material.

Engineering -

1. Evaluate Cooling Tower Blowdown Line for leaks

2. Evaluate modifying Combined Outfall Sampler pipe to prevent Cooling Tower Blowdown from interacting with groundwater

3. Evaluate Cooling Tower Blowdown cistern drain holes Maintenance/Facility -

1. Pump out the water from the cistern and obtain a sediment sample

2. Provide access to the Cooling Tower Blowdown Line site Contract - Silar Services

1. Evaluate the hydrogeologic conditions of the site and determine if there is a potential for water from that location to get off site

2. Install piezometers to measure isoconcentrations of tritium, if needed

3. Evaluate the influence of Harris Lake on the site's groundwater

Section 4 - Define the Nuclear or Personnel Safety Impact of the Problem (if applicable)

This problem does not represent a plant nuclear or personnel safety risk. The Groundwater Protection Program was implemented to provide public confidence in the nuclear industry and is enforced by the Nuclear Regulatory Commission. Even though 800 pCi/L of tritium is significantly below the 20,000 pCi/L of tritium reporting limit, any detectible tritium is a concern to the public. In order to help maintain a good relationship with the surrounding community and stakeholders the site must be proactive and efficiently deal with the problem.

Section 5 - Action Plan Actiyity Assignee Expected Date of Completion 1 Revise Silar Services contract to provide Charlie Ross/ Mike Complete services to HNP site Robinson 2 Obtain, from Silar Services, an Heather Baxter/ Don Complete 4/1/09 evaluation of the area's hydrogeologic Edwards conditions and possible impact to the public 3 Sample perched water along the Cooling Heather Baxter/ Don Complete 2/5/09 Tower Blowdown Line for tritium Edwards 4 Measure the tritiumconcentration along Heather Baxter/ Don Complete 3/4/09 the blowdown line to help isolate the Edwards possible location of a leak.

5 Obtain soil samples from the area and Heather Baxter/ Don Complete 2/5/09 cistern sediment and measure for Edwards gamma emitters 6 Evaluate the remediation required for Heather Baxter/ Don In process 4/1/09 the site Edwards 7 Document decommissioning impacts in Heather Baxter/ Don Once actions (#1-6,11) the plant 50.75(g) file Edwards are complete 8 If a leak is discovered, evaluate the Ryan Welch/ Matt In process impact of the leak upon the Cooling Denny Tower Blowdown system 9 Evaluate the cistern drain and methods Ryan Welch/ Matt In progress to prevent backflow Denny

10 Evaluate the need to modify the drain Ryan Welch/ Matt In process holes in the remaining cisterns Denny ARS 1 has been plugged 11 Evaluate the need to modify the Ryan Welch/ Matt In process Combined Outfall sampler hose Denny penetration and drain hole 12 Identify potential pathways for Heather Baxter/ Don Complete 4/1/09 groundwater migration from cistern to Edwards off-site locations through groundwater 13 If blowdown line is found leaking, Heather Baxter/ Don Complete 4/1/09 estimate the leak rate to determine if a Edwards leak of licensed material exceeds the NEI 07-07 volumetric criteria for licensed material.

14 Evaluate the location of new site Heather Baxter/Don Complete 4/1/09 monitoring wells Edwards Section 6 - References

• NEI 07-07 (Final) - Industry Ground Water Protection Initiative

" EPRI - Groundwater Protection Guidelines for Nuclear Power Plants TR 1015118, November 2007

Page  : 12 Printed: 04/29/09 00309035 ACTION REQUEST ASSIGNMENT NUMBER 06 SUB Type  : ENHN Due Date 06/01/09 Status  : AWAIT/C Reschedule Pri Resp Group: ERCCSUPT Assigned To : H BAXTER Sec Resp Group:

Subject  : ENHN-DOCUMENT IN THE 2008 ARERR REPORT THE GROUNDWATER CI Aff Facility: HNP Unit System UCR Schedule Ref Organization: Department  : 175 Discipline Est Manhrs  : Est Comp Date Assignment Status History Updated Date Updated By Assgn Status Assgn Due Date 01/05/09 GRUBBT INPROG 01/05/09 GRUBBT 06/01/09 01/05/09 GRUBBT NTFY/PRI 01/05/09 CATTCH ACC/PRI 01/05/09 CATTCH NTFY/ASG 04/28/09 BAXTEH ACC/ASG 04/28/09 BAXTEH AWAIT/C DOCUMENT IN THE.2008 ARERR REPORT THE GROUNDWATER CISTERN RESULTS Assignment Attribute Value Reqd Date BENEFIT REALIZED N Name Assignment Attribute Value Reqd Date 1 CHANGE BASIS N Name Assignment Attribute Value Reqd Date 2 COMMENTS N Name :

COMPLETION NOTES CAUSE/ACTION ASSIGNMENT COMPLETION APPROVAL Route List: 001 Route List Initiator: BAXTEH Alert Send Send Action Action PASSPORT Fac Group/Type Last Name Date Time Taken Date/Time ROBINJO2 HNP ERCCSUPT A ROBINSON 04/28/09 01:39 APPROVED 04/28/09 07:27 HNP CHUEVAL A ROBINSON 04/28/09 07:27

Groundwater Samples taken in support of Groundwater Protection Initiative NEI 07-07 Industry Groundwater Protection Initiative -

Final Guidance Document, Objective 2.4 Samples were taken at various locations throughout the plant in support of the Groundwater Protection Initiative.

Samples included the cistern enclosure of the Air Relief Valve for the Cooling Tower Blowdown Line, and Vaults and Yard Drains that may have collapsed and contain water that could potentially affect groundwater. All samples analyzed at HNP showed no detectable tritium activity. 3out of 6 samples from Cistern #2 analyzed at the Harris E&E Center showed activity less than the LLD value for the Harris Plant. The Harris E&E center analyzes to a lower LLD. An investigation is in process concerning the 3 positive results.

TRITIUM TRITIUM MANHOLE DATE (uCi/ml) MANHOLE DATE (uCi/ml)

Cistern #2 MH-523B 1/7/2008 < 1.90E-06 3/5/2008 < 1.82E-06 4/2/2008 < 1.98E-06 8/12/2008 < 1.90E-06 6/26/2008 < 2.22E-06 11/3/2008 < 2.03E-06 9/15/2008 8.78E-07 MH-523A 10/15/2008 7.47E-07 3/5/2008 < 1.82E-06 12/1/2008 7.35E-07 8/12/2008 < 1.90E-06 MH-12 B-SA 11/3/2008 < 2.03E-06 3/5/2008 < 1.82E-06 MH-519 MH-75 7/15/2008 < 1.96E-06 7/15/2008 < 1.96E-06 10/7/2008 < 1.96E-06 10/7/2008 < 1.96E-06 MH-511B MH-72D-SB 4/8/2000 < 1.88E-06 1/26/2008 < 1.87E-06 7/2/2008 < 2.02E-06 7/1/2008 < 1.96E-06 9/23/2008 < 2.02E-06 8/12/2008 < 1.90E-06 MH-511A 9/22/2008 < 1.91E-06 3/5/2008 < 1.82E-06 12/15/2008 < 1.72E-06 11/6/2008 < 2.03E-06.

MH-72A-SA MH-51 3/5/2008 < 1.82E-06 10/7/2008 < 1.96E-06 11/6/2008 < 2.03E-06 MH-505E MH-71D-SB 1/26/2008 < 1.87E-06 1/26/2008 < 1.87E-06 4/8/2008 < 1.88E-06 7/1/2008 < 1.96E-06 9/15/2008 < 2.03E-06 9/22/2008 < 1.91E-06 10/13/2008 < 1.95E-06 12/15/2008 < 1.72E-06 12/15/2008 < 1.72E-06 MH-71B-SB MH-505B 3/5/2008 < 1.82E-06 1/26/2008 < 1.87E-06 8/12/2008 < 1.90E-06 3/5/2008 < 1.82E-06

11/6/2008 < 2.03E-06 4/8/2008 1 < 1.88E-06 MH-70D 7/29/2008 < 1.86E+06 1/26/2008 < 1.87E-06 9/2/2008 < 1.90E-06 7/1/2008 < 1.96E-06 9/23/2008 < 2.02E-06 9/22/2008 < 1.91E-06 11/26/2008 < 1.90E&06 12/15/2008 < 1.72E-06 MH-505A MH-69 3/5/2008 < 1.82E-06 10/7/2008 < 1.96E-06 11/6/2008 < 2.03E-06 MH-61 MH-503 2/20/2008 < 1.85E-06 7/29/2008 < 1.86E-06 7/29/2008 < 1.86E-06 MH-43 10/14/2008 < 1.92E-06 7/15/2008 < 1.96E-06 MH-59 MH-41 10/14/2008 < 1.92E-06 10/7/2008 < 1.96E-06 MHR525E < MH-31 7/2/2008 < 2.02E-06 7/29/2008 < 1.86E-06 12/15/2008 < 1.72E-06 MH-29 MH-523D 7/29/2008 < 1.86E-06 1/26/2008 < 1.87E-06 MH-27 7/1/2008 < 1.96E-06 7/29/2008 < 1.86E-06 10/14/2008 < 1.95E-06 MH-23 MH-17 9/15/2008 < .1.91E-06 7/29/2008 < 1.86E-06 MH-19 10/14/2008 < 1.92E-06 10/14/2008 < 1.92E-06