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{{#Wiki_filter:6-,,e,ýOA liýýO+ eAU44-1 ROOT CAUSE REPORT TITLE:          Inadequate response to unplanned environmental tritium releases from Braidwood Station due to weak managerial oversight and the lack of integrated procedural guidance.
Unit(s):                            Braidwood Units 1 and 2 Event Date:                          11/30/2005 Event Time:                          11:50 Action Tracking Item Number:        428868 Report Date:                        02/14/06 Sponsoring Manager:                I Janice Kuczynski Investigators:        Position "Jason Eggart      /
Braidwood Chemistry Lead Investigator
'Tom Leffler            Root Cause (RC) Qualified Investigator Randy Kalb            Dresden Chemistry Investigator Kim Aleshire          Braidwood EP (ODCM) Investigator Glen Vickers          LaSalle RP Investigator Scott Kirkland        Quad Cities Investigator Jim Crawford        I  BWD CMO RC Qualified Investigator Mike Miller            Braidwood Operations Jeff Burkett          Braidwood Operations Dan Stroh              Braidwood Engineering Carl Dunn              Senior Mentor Executive Summary:
Reason for Investigation:
Braidwood Station identified low levels of elevated tritium in the groundwater on and in the vicinity of Braidwood Station property (See Attachment 7 for Map). The presence of these elevated levels exceeds levels specified in Illinois EPA regulations (Attachment 10). The Illinois Environmental Protection Agency (IEPA) groundwater limit for tritium concentration parallels the Federal EPA regulation for annual radiation limits due to drinking water radioactivity. The statutes imply that four (4) mrem would not be exceeded if less than two liters of water at the IEPA limit were.:.
ingested daily for a year. In addition, the U.S. Nuclear Regulatory Commission (NRC) provides limnits on liquid effluent releases and how those effluents must be
 
monitored and reported. The NRC has reached a preliminary conclusion that Braidwood may not have satisfied all associated regulations in this regard. When the inspection exit for the current NRC review is completed, any potential violations will be entered into the Braidwood Corrective Action Process. This report provides insights on the causes of these potential violations and associated corrective actions. Additional investigation will be performed commensurate with the content of any such potential violations.
Scope of the Review:
The first focus of this root cause investigation is to determine the root cause(s) of and appropriate corrective actions for the unplanned tritium releases from Braidwood Station (See Attachment 1). The Braidwood Tritium Remediation Team has responsibility under Action Request (AR) 435383 for corrective actions to prevent future unplanned tritium releases to the environment and to remediate the existing condition of detectable tritium in groundwater on and in the vicinity of Braidwood Station property. The second focus of this root cause team is to evaluate the effectiveness of Braidwood's response to the Circulating Water (CW) Blowdown (BID) leaks, which deposited tritiated water on the ground during 1998 and 2000 as well as during the smaller volume leaks, which both preceded and succeeded the 1998 and 2000 leaks. If this investigation determines that Braidwood's response actions were not effective, this root cause team will determine the root cause(s) and appropriate corrective actions for those ineffective response actions.
Root Causes and Corrective Actions to Prevent Recurrence (CAPRs):
The root cause of the large volume leaks in 1998 and 2000 is documented in Root Cause Report (RCR) 38237, which determined that the Circulating Water (CW)
Blowdown (B/D) Vacuum Breaker (VB) Valves had inadequate preventative maintenance programs and inadequate design configuration (Root Cause 1). The Corrective Actions to Prevent Recurrence (CAPRs) from RCR 38237 were to institute a Preventative Maintenance Program and system modifications, which are complete and have been verified to be effective in preventing major vacuum breaker valve failures that resulted in large volume spills (CAPR 1). The root cause of the small tritiated water leaks, which both preceded and succeeded the 1998 and 2000 leaks, was that the need for a near zero leakage standard was not identified due to a then-existing lack of Technical Rigor/Questioning Attitude (Root Cause 2). The Braidwood Tritium Remediation Team will determine the methodology and implement the plan for future radiological releases, including leakage standards under IR 435383 and effectiveness review ATI# 428868 (CAPR 2). HU-AA-102 and HU-AA-1212, Technical Human Performance Practices and Technical Task Risk/Rigor Assessment, Pre-Job Brief, Independent Third Party Review, and Post-Job Brief procedures have been instituted to improve technical rigor, questioning attitude, and attention to detail (CAPR 3).
2
 
This Root Cause Team determined that Braidwood's response to the 1998 and 2000 events was ineffective. The response to the 1998 and 2000 releases of radioactivity (tritium) to an unplanned location is indicative of ineffective corrective actions. As directed by the root cause charter (Attachment 1), these ineffective corrective actions are addressed in this root cause report.
The first root cause for the ineffective response was a lack of integrated procedural guidance to ensure proper recognition, evaluation, and timely mitigation of the radiological spill events (Root Cause 3). Integrated procedures will be developed and implemented to provide detailed spill and leak response requirements which will ensure full compliance with 3
 
State and Federal laws and regulations and to integrate Exelon resources to respond to radiological leaks and spills (CAPR 4). A second root cause for the ineffective response was weak management review and oversight of spill response activities (Root Cause 4).
Specifically, management had a weak questioning attitude and an inadequate challenge culture regarding the 17 CW B/D leaks over the 10 year period bridging 1996 to 2006. Exelon Corporate, the Issues Management Team, and Braidwood Senior Management did not track characterization and mitigation plans to completion during and following the year 2000 spill. HU-AA-102 and HU-AA-1212, Technical Human Performance Practices and Technical Task Risk/Rigor Assessment, Pre-Job Brief, Independent Third Party Review, and Post-Job Brief procedures have been instituted to improve technical rigor, questioning attitude, and attention to detail (CAPR 3).
OP-AA-106-101-1002, Exelon Nuclear Issues Management, will be revised to: 1) improve Corrective Action Program (CAP) controls of Issues Management teams, 2) utilize the tools and techniques of the Exelon HU-AA-102 and HU-AA-1212, Technical Human Performance Practices and Technical Task Risk/Rigor Assessment, Pre-Job Brief, Independent Third Party Review, and Post-Job Brief procedures, 3) strengthen reporting requirements to station Senior Management, and 4) define station Senior Management responsibilities for oversight and challenge of events and issues from initial identification to final disposition (CAPR 5).
Extent of Condition:
Exelon Nuclear is evaluating the potential for unplanned tritium releases at each of its facilities, with added emphasis on Pressurized Water Reactors due to tritium production rates. Nuclear Event Report (NER 428868-12) will require all Exelon Sites to take actions to research historical spills and determine if tritium remediation is required. The nuclear industry will be informed of the issue through a Nuclear Network Operating Experience Report (NNOE 428868-13).                    Other spill type (Hazardous Material) response procedures were reviewed and determined to have effective guidance through the Hazmat and Environmental programs (Attachments 2
& 8). These programs and procedures will receive further review and update to integrate radiological interfaces (CAPR 3).
4
 
Risk Assessment/ Reportability:
The Nuclear Safety Risk Assessment showed no impact on station operation or response to postulated accident conditions. The event was reportable under Reportability Manual, SAF 1.9, News Release or Notification of Other Government Agencies per 10 CFR 50.73.
Previous Events:
Since 1996, 17 CW B/D valve leaks were noted in the Braidwood Corrective Action Database and Work Control System as documented in Table 1 of this report in the Events Description Section. Responses varied from a request for a normally scheduled repair to immediate remediation efforts. The best response, which occurred in year 2000, removed water from the spill area, but did not effectively determine the extent of condition for full remediation.
Condition Statement:
In response to an Illinois Environmental Protection Agency (IEPA) inquiry in March 2005, Braidwood Station began taking a series of groundwater samples within Braidwood Station property boundaries. Some of those samples identified elevated levels of tritium in the Braidwood Station groundwater. Issue Report (IR) # 328451 documented these monitoring results in April 2005. This sampling continued over a period of eight months.
In response to the results of these initial and follow-up monitoring samples, an Issues Management Team was formed on November 30, 2005 in accordance with Exelon procedure OP-AA-106-101-1002. Additional sampling resulted in elevated tritium levels being identified in groundwater in the vicinity of Circulating Water (CW)
Blowdown (B/D) system Vacuum Breakers (VB) #2 and CW B/D VB #3, which had experienced large volume leaks in 1998 [(VB 3) Problem Identification Form (PIF) #
Al 998-04324] and in 2000 [(VB 2) IR # 38237].
On 30 November 2005, the Issues Management Team (IMT) initiated IR# 428868 reporting that elevated levels of tritium had been detected in onsite groundwater sampling wells and triggering this root cause investigation and report. Subsequent sampling identified elevated tritium levels outside Braidwood Station property boundaries.
On 16 December 2005, the Illinois Environmental Protection Agency (IEPA) issued Violation Notice W-2005-00537 to Exelon Generation - Braidwood Station, alleging Impairment of Resource Groundwater.
See Attachment 6 for an overview of the Circulating Water (CW) Blowdown (B/D)
System operation. See Attachment 7 for a map of the affected areas.
5
 
Event
 
== Description:==
 
Braidwood Station identified elevated levels of tritium in the groundwater that exceed Illinois EPA regulations (Attachment 10). Due to the extended period of time and the number of events covered in this root cause investigation, the timeline became very complex. For clarity, the Event Description has been organized as follows:
The Events and Causal Factors (E&CF) Chart has been placed in Attachment 4.
Page 1 of 3 of the E & CF chart depicts the timeline for all vacuum breaker issues.
Page 2 of 3 and page 3 of 3 depict barrier analysis of the events on VB-2 and VB-3.
Displayed in this event description section are:
: a. Table 1, Circulating Water (CW) Blowdown (B/D) Leak Table, which details the leaks that have been identified during this investigation.
: b. Event timeline summary with events that led up to this Root Cause Investigation.
: 1. Attachment 12, CW B/D VB-2 and VB-3 detailed timelines.
: a.        Leaks that are within the scope of this investiqation The elevated levels of tritium have been determined to have originated from historical spills from the CW B/D system. Since 1996, 17 CW B/D vacuum breaker leaks were noted in the Braidwood Corrective Action Database and work control database. The following table is a summary of leaks identified from records, including the station's response.
This team did not locate any computerized records of the Work Orders or Problem Identification Forms (PIFs) prior to approximately 1996. As such, the quantification of and response to these events had to be recreated from historical documents and interviews of involved personnel. Two means of identifying the impact of potential leaks from initial plant operation in 1988 to 1996 were considered. The first was to pull microfiche records for review and the second was to perform direct characterization of the conditions in the vicinity of all of the Circulating Water (CW)
Blowdown (B/D) Vacuum Breakers (VBs).
Because of the need to have full confidence in the characterization of conditions in the vicinity of the vacuum breakers, the decision was made to install both deep and shallow monitoring wells in the vicinity of all of the CW B/D vacuum breakers. This was determined to be preferable to depending on locating microfiche records for possible leaks and monitoring only those locations.
6
 
Table 1: CW BID Leak Table
 
===RESPONSE===
PIF/    Immediate Particulate Tritium            10 CFR
#  Date      Event      Leak Size    WR      CRAIR        Action    Sample        Sample      50.75(g)            Resolution l 11/27/96 VB-1        -250,000      WO,  'rocess had Requested No 1996            No 1996      No 1996    06/19/97 1" pipe to air leak    gals        96111970 personnel      repair., documents documents documents              release valve broke.
decide                    found.        found.      found. Tritium plume was WR or                    Will be        Tritium    Will be    identified around VB-I PIP. So,Reeito oPIF, WR                  addressed    plume was addressed        in 2006. Remediation only.                under ATI# identified in under ATI#      being addressed under 435383      2006. Will    435383      IR# 435383.
be addressed under ATI#
_435383 2    1/5/98 VB-2 leak Small leak. WR# 1rocess had Requested No 1998              No 1998      No 1998      11/08/00 replaced the 98000682 personnel      repair    documents documents        documents    float, replaced vacuum decide                    found.        found.      found. breaker and isolation WR or                    Will be        Tritium    Will be    valve. Tritium plume PIF. So,                addressed    plume was    addressed    was identified around o l WR                  under ATI# identified in    under ATI#    VB-2 in 2005.
only.                  435383      2005. Will    435383      Remediation being be addressed                addressed under IR#
under ATI#                435383.
435383 3  12/4/98 VB-3        Caused        WO    A1998-      Isolated    04/26/01      No 1998      07/25/01    05/20/02 1" pipe to the leak - seat flooding. - 98127749 04324      air release      Soil      documents    evaluation    air release valve broke 3M gals                          valve until Particulate        found.      detected    due to corrosion. Guide
* parts    radioactivity    Tritium    particulate  post sheared weld off could be        above      plume was  radioactivity, float. Entire vacuum received, background. identified in                  breaker replaced (July This                    2005. Will                2001). Tritium plume stopped                  be addressed                was identified around this                  under ATI#                  VB-3 in 2005.
leakage.                    435383                  Remediation being addressed under IR#
_435383.
4  11/6/00    VB-2    Caused        WO      A2000-    Replaced    Particulate      Tritium        Yes.      11/06/00 Float broke on leak-    flooding. - 98003276 04281      vacuum      radioactivity  plume was Sampling        vacuum breaker. Tritium seat    3M gals                Root      breaker    above            identified    detected    plume was identified Cause                background. around VB-2 particulate        around VB-2 in 2005.
38237                                  in 2005. radioactivity. Remediation being Will be                addressed under IR#
addressed                435383.
under ATI#
435383 5 11/10/00 VB-6        Small leak    WO        None. Requested No 2000              No 2000      No 2000          10/17/05 Valve leak                  99231846 IR should repair. documents documents documents                    assembly replaced. 2006 have been                  found.        found,      found.      remediation sampling seat                            written.                  Will be          2006        Will be    showed no tritium in the addressed      samples    addressed      groundwater at this under ATI# show no          under ATI#            location.
435383 tritium in the        435383 groundwater_
7
 
===RESPONSE===
PIF/    Immediate Particulate Tritium          10 CFR                        -
#  Date      Event      Leak Size    WR CR/IR        Action    Sample        Sample      50.75(g)        Resolution 6 11/20/00    VB-1    Vacuum        WO    None. Rebuilt    11/20/00        Tritium        Yes. 11/21/00 Rebuilt valve leak    breaker    99233404    IR      valve,    samples        sampling    Sampling  internals. Tritium lifting.            should                reported          was      reported  plume was identified have              negative for performed negative for    around VB-1 in 2006.
been                detectable no detectable detectable    Remediation being written.          radioactivity, activity. radioactivity  addressed under IR#
1_                                      435383.
7  6/18/01    VB-3    1/2 GPH leak    WO 4,2001- Sampled          No 2001        Tritium    No 2001  05/20/02 Rebuilt leak  from main 98127749 01806      water,    documents plume was documents          valve. Tritium plume vacuum                                      found.      identified    found. was identified around breaker.                                    Will be around VB-3 Will be          VB-3 in 2005.
addressed in 2005. Will addressed      Remediation being under ATI# be addressed under ATI#      addressed under IR#
435383      under ATI#      435383  435383.
435383.
8  6/18/01    VB-9    Water in      N/A    A2001- Sampled Negative for No 2001              No 2001  No active leak.
vault.                01806    water,    detectable documents documents        Attributed to particulate    found. No      found. groundwater, 2006 adioactivity. tritium in        2006  remediation sampling groundwater remediation  showed no tritium in at this    sampling  the groundwater at this location  showed no  location.
reported in    tritium.
2006.
9  6/18/01  VB-10    Water in      N/A    A2001- Sampled Negative for No 2001              No 2001  No active leak.
vault                01806    water,    detectable documents documents        Attributed to particulate    found. No      found,  groundwater. 2006 radioactivity. tritium in      Will be  remediation sampling groundwater addressed    showed no tritium in at this  under ATI#  the groundwater at this location in    435383  location.
2006.
10  6/18/01  VB-11    Water in      N/A A2001- Sampled          No 2001        No 2001      No 2001        No active leak.
vault                01806    water. documents documents documents                Attributed to found,      found. No      found. groundwater. 2006 Will be        tritium in    Will be  remediation sampling addressed groundwater addressed          showed no tritium in under ATI#        in 2006. under ATI#  the groundwater at this 435383                      435383          location.
11  5/4/02    VB-3    Seepage      WO    106767 Requested      Sample      Per IR, RP    No 2002  05/20/02 replaced air leak - vent              0440231            repair. showed            was    documents  elease valve. Tritium above    sampling. No found.      plume was identified background documents          Will be  round VB-3 in 2005.
particulate found. Will addressed        Remediation being activity. Will be addressed under ATI#  addressed under IR#
be addressed under ATI#        435383          435383.
under ATI#        435383 435383 8
 
===RESPONSE===
PIF/  Immediate Particulate    Tritium      10 CFR
#  Date    Event    Leak Size    WR CRJIR        Action    Sample      Sample        50.75(g)        Resolution 12  8/20/03 VB-4  1 gpm to      WO    172376  None        Sample      No 2003      No 2003    9-9-03 replaced seat seat  vault, no    99243232                      analysis    documents    documents    ring/float and top flooding                                detected no      found.      found,          gasket.
particulate    Tritium      Willbe radioactivity plume was      addressed 8/27/03                              173204  Stopped                identified in under ATI# Tritium plume was mod                  2006. Will 43538310. identified around VB-testing.              be addressed                    4 in 2006.
under ATI#                  Remediation being 435383                  addressed under IR#
435383.
13  9/11/03 VB-4  20-40          WO    175241 Secured      No 2003      No 2003      No 2003    10/22/03 No work seat  drops/min    99243232        booster    documents    documents documents        performed. Leak pumps.        found.        found.      found. determined to be from Will be      Tritium      Will be operating the system at addressed    plume was addressed        low flow. Tritium under ATI#  identified in under ATI# plume was identified 435383      2006. Will    435383    around VB-4 in 2006.
be addressed                Remediation being under ATI#                addressed under IR#
435383                        435383.
14 11/18/04 VB-8  Popping /      WO 274328    Isolated    No 2004      No 2004      No 2004    10/18/05 replaced leaking,      0757898        Vacuum      documents    documents    documents valve assembly. 2006 small leak                    breaker        found.        found.      found. remediation sampling within pit                                                                        showed no tritium in the groundwater at this location.
15  5/19/05 VB-I  20 drop per    WO 336401      Isolated    No 2005        Yes.      Will be  12/18/05 replaced the minute leak )0744194          valve and  documents      Sampling    addressed    vacuum breaker from the air and WR          requested      found,          was    under ATI#    assembly. Tritium release      D0178930          repair.                performed. 435383    plume was identified valve.                                                    Tritium                around VB- I in 2006.
plume was              Being addressed under identified in                  IR# 435383.
2006. Will be addressed under ATI#
435383 16  5/24/05 VB-6  Seepage        WO    338111 Isolated    No 2005        Per IR,      Will be  10/19/05 rebuilt main seat from float/ 00820879          leaking    documents      sampling    addressed valve and replaced air seat area                    vacuum      found,            was    under ATI# release valve. 2006 with one                      breaker.                  performed. 435383    remediation sampling foot of water                                                                    showed no tritium in in pit.                                                                        the groundwater at this l6cation.
9
 
===RESPONSE===
PIF/ Inunediate  Particulate    Tritium      10 CFR
#  Date      Event      Leak Size    WR CR/IR      Action      Sample      Sample      50.75(g)      Resolution 17 1/16/06    VB-7      Bushing        WO 442540    Reduce      Sample          No        Will be  Pending EACE in failure. Not  0883925      B/D. Take      analysis    detectable addressed progress. Tritium plume significant..              samples. detected no tritium in        under  was identified around Evaluated    particulate surface water ATI#      VB-7 in 2006, but was for    radioactivity from this      435383    due to historical regulatory              leak. Prior to          leakage. Remediation complianc                  this leak,            being addressed under e, isolated              tritium above                IR# 435383.
valve and                background wrote WR                    & below EPA drinking water limit identified in 2006 in wells used to characterize conditions near this vacuum breaker.
Responses varied from a request for normally scheduled repairs to an immediate remediation effort. The 2000 response effectively remediated the surface spill area, but did not effectively characterize the extent of condition to allow for full remediation due to weak management review and oversight of spill response activities (Root Cause 4). A contributing cause common to many of the documented events is the lack of questioning attitude and oversight by Braidwood Senior Management to the radiological implications of blowdown spills. Issue ownership and follow through were lacking in all levels of management. Corrective actions 2 and 3 address training for all levels of management.
The tritium remediation plan will be tracked to completion under IR# 435383 and CAPR 2. The Braidwood Tritium Remediation Team has performed tritium characterization for the Circulating Water (CW) Blowdown (B/D) Vacuum Breakers (VBs) and performed integrity tests of the blowdown line. As of January 31, 2006, CW B/D piping acoustic testing determined that no leak above 1.0 gpm existed (minimum detectable level of testing equipment). The characterization of tritium levels in the vicinity of the vacuum breakers is described in Table 1. The station secured radioactive releases to the blowdown line on 11/23/05 and releases will remain secured until the tritium remediation team issues the final resolution under ATI# 435383-07.
10
: b. Event timeline with events that led up to this Root Cause Investigation October 1990 "DRAFT" Commonwealth Edison procedure, CSG-001, "General Action Plan for Response to Unmonitored Releases and Very Low Level Radioactive Spills" was developed in 1990 but not implemented. This procedure contained guidance for mitigating intrusion of low-level radioactive spills into the groundwater. The reason the procedure was not implemented could not be identified. The failure to implement this procedure was not determined to be a root cause for three reasons. First, this procedure did not provide overall integrated guidance for spill evaluation and mitigation. Second, the reason the procedure was not implemented could not be identified. Third, no corrective action to prevent recurrence could be determined.          Therefore, the lack of integrated procedural guidance to ensure proper recognition, evaluation and timely mitigation of the radiological spill events was considered a root cause (Root Cause 3) for the ineffective response to Circulating Water (CW)
Blowdown (B/D) Vacuum Breaker (VB) leaks (Causal Factor 3, Root Cause 3).
1991
* Illinois regulation 35 IAC 620 enacted, which places radioactivity limits on potable resource groundwater tritium concentration. This new regulation was not integrated into Company Procedures (CausalFactor6).
November 26, 1996
* Found 1" pipe from VB-1 to the air release valve failed. Estimated 250,000 gallons released to the ground.
In 1996, VB-1 had a leak of approximately 250,000 gallons due to an air release valve failure. The only documented response to this event was a work order (96111970) to isolate and repair the valve. The work control process (currently Exelon procedure WC-AA-106) had no guidance for prioritizing radiological leaks which could enter the groundwater. (Failed Barrier 5). In the absence of any other recognized hazard, the current process prioritizes these work orders as a "C".
Corrective action 26 will revise WC-AA-106. No documentation could be found to indicate that any actions were taken to remediate the spill or address the potential radiological concerns. Since there was no Problem Identification Form (PIF) written to document the failure, there is no record of review of this event by Braidwood Senior Management. During this team's review of this event, the team could not find any documentation of sample analysis for radioactivity.
11
 
Station actions and interviews of site personnel documented that in the past, personnel did not respond to CW B/D leaks as an offsite radioactive release.
Rather, they focused on preventing. potential National Pollution Discharge Elimination System (NPDES) violations.        As long as the effluent (water) did not leave Exelon property, personnel did not always perceive a reason for concern, as NPDES requirements were considered met. The site personnel interviewed, that were present at the time of the 1996 event, were unaware of the Illinois regulation regarding groundwater tritium limits. Engineering walkdown Preventative Maintenance (PM) procedure (currently Exelon Braidwood procedure ER-BR-400-101) and Operations Department (OPS) walk down PM procedure (currently Braidwood procedure OBwOS CBW-A1) did not contain any precautions or steps for addressing CW B/D spills that potentially contain tritium (Failed Barriers 12 & 13).
Operational procedures BwOP CW-12, BwOP WX-526TI and BwOP WX-501TI had no guidance to isolate the B/D system if a known leak had occurred during a routine radiological release to the Kankakee River (Failed Barriers 15, 16, & 17).
No documentation was located that implied a recognition of vacuum breaker leakage impact on the requirements of the ODCM, REMP (Radiological Effluent Monitoring Program), and 10CFR50.75(g). The 1996 Annual Effluent Report did not contain an evaluation of the vacuum breaker radioactivity released and did not contain the associated evaluation of the dose to the public (IR 455079) & (CA-15).
NOTE:
As of January 2006, Elevated levels of tritium have been identified in the groundwater on Braidwood Station property close to VB-I. In one location on Braidwood property, the level of tritium was above the Illinois EPA ground water standards (20,000 picoCuries/liter). At Braidwood Station there was no site or corporate procedure for guidance on low-level radioactive spills (Failed Barriers 4 & 6). The Hazmat procedures (BwAP 750-4 & BwAP 1100-16) did not address radiological spills (Failed Barriers 1 & 2).
December, 1998
* Leak from VB-3. (See Attachment 12 for more details.)
November 20, 2000
* Leak from VB-1.
12
 
November, 2000
* Leak from VB-2. (See Attachment 12 for more details.)
December 2000
* VB-2 Root Cause Report 38237 for equipment failures was completed.
December, 2004 Based on Operating Experience from the nuclear industry (OPEX),
Braidwood Station commenced increased investigation of environmental tritium.
January, 2005 Exelon chartered an investigation into tritium OPEX issues, with Braidwood Station providing a multi-disciplined team to support the efforts to better understand and mitigate environmental tritium issues.
March 17, 2005
* On March 17th, the Illinois Environmental Protection Agency (IEPA) notified Exelon Nuclear Corporate Environmental that they were investigating tritium concentrations in wells near Braidwood Station in preparation for the Godley public hearing on Braidwood Station's NPDES permit renewal. [The Root Cause Team could not find evidence of entry of this item into the Corrective Actions Program (Missed Opportunity)].
" The IEPA was working with Exelon Nuclear Corporate Environmental to understand why one of the Braidwood Radiological Effluent Monitoring Program (REMP) wells along the Kankakee River was indicating about 400 pCi/L concentration of tritium. [Since initial REMP sampling was commenced, the Braidwood REMP reports documented two wells along the Kankakee River with elevated tritium (within limits). One well returned to background levels when the well was redrilled (new casing)]
" The IEPA was investigating why shallow groundwater well #2 in Godley was reported to have tritium. (Exelon Corporate Environmental log documents that Exelon, an independent contractor, and the IEPA analyses could not confirm any tritium above background levels in any of the Godley, IL wells.)
13
 
March 23, 2005 The Exelon Corporate Environmental log documents that Exelon, an independent contractor, and the IEPA analyses of samples from wells in Godley Illinois did not detect any tritium above background levels.
In preparation for the upcoming public meetings for the city of Godley, the IEPA requested (by phone) Exelon Corporate Environmental to have Braidwood Station sample for tritium at the following locations:
: 1. The cooling lake discharge canal
: 2. The northwest corner of the cooling lake
: 3. The two monitoring wells used for the previous environmental remediation sampling on the west side of the Turbine Building.
" The IEPA was informed that Exelon installed wells to determine a groundwater gradient near the blowdown line spill at VB-2 that occurred in November 2000. These wells were installed for hydrology analysis.
* The IEPA requested that Exelon provide a sample of the offsite drainage ditch and samples from the four shallow monitoring wells that were installed in the area of the November, 2000 blowdown line leak.
* The IEPA asked Braidwood Station to sample the shallow Godley well, which was reported to be contaminated with tritium, because the Agency would like to have a recent tritium analysis on it.
March 24, 2005 An Independent contractor sampled the following per IEPA March 23, 2005 request:
: 1. The cooling lake in the discharge canal
: 2. The cooling lake in the northwest corner
: 3. The two monitoring wells used for the previous environmental remediation sampling (two wells closest to the Turbine Building)
Additional Exelon samples:
: 4. The cooling lake on the east-west dike approximately halfway in the middle
: 5. The offsite drainage ditch
: 6. The four shallow monitoring wells that were installed in the area of the November 2000 blowdown line leak 14
 
April 1, 2005 Results (reference Braidwood Chemistry Department Sample Log) from the March 24 tritium samples taken at Braidwood Station indicated presence of tritium above background in the following locations (See Attachment 7 for Map):
: 1. The cooling lake in the discharge canal - < background
: 2. The cooling lake in the northwest corner - < background
: 3. Sample point MW-4, near the November 2000 VB-2 leak -. above background Sample point MW-6, West side of Turbine Building - above background Additional Exelon samples
: 4. The cooling lake on the east-west dike approximately halfway in the middle - < background
: 5. Sample point BD-101, Braidwood drainage ditch - above background
: 6. The four shallow monitoring wells that were installed in the area of the November 2000 blowdown line leak. Three were < background.
One was above background The levels identified in these samples were well below the federal standard of 20,000 picoCuries/liter (pCi/L).
* Although the tritium levels were well below federal standards, Braidwood commenced detailed sampling and investigation.
April 15, 2005 Exelon sent Godley well results and the second sample on the drainage ditch to the IEPA. Samples had been collected on April 7, 2005:
Sample Location                Sample ID            Result BD-101 (Drainage Ditch)        BDSW-1 665          twice background Godley Rec. Center            BDWW-1666            less than background Godley Rec. Center              BDWW-1 667          less than background April 25, 2005 IR 328451 was generated to identify tritium levels above background in the Braidwood drainage ditch.
15
 
May 5, 2005
* Additional samples were taken at three locations in and around the Braidwood drainage ditch in an attempt to better define the source of the tritium.
May 9, 2005
* Due to the results of the March 24, 2005 sample and confirmatory sampling of Braidwood drainage ditch, Braidwood Station expanded the sampling and investigation to focus on both surface water and groundwater sample points.
May 10, 2005 Five shallow groundwater wells (GW-1, GW-2, TW-20, OW-32 and OW-
: 33) were sampled (See Attachment 7 for Map). These five wells are located onsite and are positioned between the Braidwood drainage ditch and the Village of Godley. These samples were to provide more detailed information to samples previously collected on May 5. No tritium was detected above background concentrations in any of these five samples.
May 17, 2005
" A conference call was held with IEPA to exchange recent sample results and to discuss sampling in the Braidwood Station onsite wells (GW-1, GW-2, TW-20, OW-32 and OW-33) (See Attachment 7 for Map). The IEPA reported all tritium samples as less than background, which corroborated the site's results.
" The IEPA stated that they would acquire four samples from residents in Godley who live along side the drainage ditch and would analyze the samples for tritium. The Agency would provide duplicate samples for Exelon tritium analyses and would notify us when the sampling was scheduled.
May 18, 2005 A 20 drop per minute leak from the pilot valve of vacuum breaker #1 (VB-
: 1) was identified during a walk down by Braidwood Engineering. A sample was acquired and sent for analysis. (See Attachment 7 for Map) 16
 
May 19, 2005 The tritium concentration in the sample of the leak catch tray at the VB-1 leak was above the IEPA standard for groundwater. (There was no evidence of leakage outside of the catch tray).
May 23, 2005
" Braidwood Station briefed the Nuclear Regulatory Commission (NRC)
Inspector from the Region III Office on the drainage ditch tritium results.
An overview of the sampling performed to date, along with the results of the sampling and a copy of the collated sample results, were presented to the NRC as part of the routine Offsite Dose Calculation Manual (ODCM)/Radiological Environmental          Monitoring  Program (REMP) inspection.
* Tritium analyses performed on five water samples collected at Braidwood Station on May 20, 2005 were less than background except for the VB-3 Pit tritium concentration which was above background (See Attachment 12 for VB-3 timeline).
June 14, 2005
* Exelon and IEPA acquired four samples from the Godley wells per the May 17 request.
June 20, 2005
* As part of the investigation to determine the source of tritium, the station received the independent contractor proposal to install monitoring wells to focus on:
o    Examining the groundwater impact in the area of VB-1 located south of the switchyard o    Determining the movement and direction of groundwater and its relationship to surface water on both the east and north side of the Braidwood Station property June 28, 2005
* The results of the four Godley well samples taken on June 14, showed no tritium levels above background.
17
 
July 22, 2005 Exelon installed monitoring wells to investigate potential leakage around VB-1 and VB-3 that may be contributing to leakage in the Braidwood drainage ditch: (See Attachment 7 for Map) o  Sample  point MW-1 06, near the fresh water holding-pond o  Sample  point MW-1 07, SE corner of the switchyard near VB-1 o  Sample  point MW-108,  east of VB-1 near the CW B/D line o  Sample  point MW-1 09, east of the switchyard near the Braidwood ditch September 23, 2005 Exelon pursued additional resources to expand the scope of the tritium investigative activities to more clearly define the source of the tritium, which had been discovered in the drainage ditch. This information was communicated by phone to the IEPA.
October 2005
* Exelon installed monitoring wells as part of an expanded scope of the tritium investigation: (See Attachment 7 for Map) o    Sample point MW-110, north of the meteorological tower o    Sample points MW-111, MW-112, and MW-113, north property line near Smiley Road October 25, 2005 Initiated IR# 390133 to address difference between historical annual liquid discharge curie content and the UFSAR description. Investigation of this difference determined that no change was required.
November 9, 2005 Two of the four groundwater samples collected on October 19 and October 20, 2005 from the new monitoring wells exceeded the Offsite Dose Calculation Manual (ODCM) Lower Limit of Detection of 2000 pCi/L.
Upon this indication, Braidwood Station assembled an Exelon Issues Management Team (OP-AA-1 06-101-1002) to evaluate the tritium issue.
18
 
November 22, 2005 Nuclear Oversight (NOS) completed the ODCM, REMP, Effluent and Environmental Monitoring Audit Report, NOSA-BRW-05-08 (AR# 287718).
NOS found no issues of note. NOS did not identify that the ODCM did not include Illinois State Groundwater Regulations (Failed Barriers 28 & 29).
November 23, 2005
* Braidwood Station terminated the use of the Circulating Water (CW)
Blowdown (B/D) system for radioactive liquid releases pending resolution of this root cause investigation and appropriate corrective actions.
November 30, 2005
* Issues Management Team was formed to address tritium issues.
December 2, 2005
* Emergency Notification System (ENS) notification made to the NRC due to the notification of other -government agencies' (IEPA) and a press release.
January 15, 2006 As this RCR was being finalized, a leak occurred on VB-7 due to failure of an internal guide and was documented on IR# 00442540. (See analysis section of how this issue is addressed) (See Attachment 7 for Map)
* The standing water posed no radiological concern because CW B/D radiological releases had been held in abeyance since November 23, 2005.
* The standing water in the vicinity of VB-7 was sampled for gamma radioactivity and tritium (no radioactivity detected) and evaluated for NPDES compliance. An environmental specialist verified that the leakage did not reach runoff ditches or creeks and therefore NPDES requirements were met.
* Prior to this leak, tritium above background and below the EPA drinking water limit was identified in 2006 in wells used to characterize conditions near this vacuum breaker. The source of this tritium is likely to be leakage prior to 1996 as no record of leakage subsequent to 1996 could be located.
19
 
Analysis:
The Root Cause Investigation Team interviewed personnel and reviewed the response procedures, regulations, historical documentation, and environmental impacts. An Event and Causal Factor (E&CF) Chart (Attachment 4) was utilized for Cause and Effect Analysis (Attachment 3), Change Analysis (Attachment 5) and Barrier Analysis (Attachment 2).
Unplanned Tritium releases from Braidwood Station:
The 2000 event Root Cause Report (RCR) 38237 CAPR's addressing the vacuum breaker failures were reviewed and have been determined effective in preventing major vacuum breaker failures since 2000 through the end of 2005. The purpose of the Root Cause in 2000 was to determine the cause of those failures. RCR 38237 CAPR implemented a revised preventive maintenance program for the float operated vacuum breaker valve assemblies for the CW B/D and Makeup Systems.
This Preventative Maintenance (PM) was developed to include specific intervals for inspection of valve internals and provided for periodic replacement of the valves (refer to Attachment 6 for CW B/D description). This team concludes that the RCR 38237 CAPRs have effectively prevented recurrence of the large volume leaks (as described in Table 1) caused by corroding valves that did not receive effective PMs and water hammer damage due to design configuration. Currently, daily walkdowns of the blowdown vacuum breakers are being performed to verify that no leakage is occurring.
On January 16, 2006, a leak occurred on VB-7 due to failure of an internal guide bushing and was documented on IR 00442540. EACE 442540 is performing an evaluation of this failure. The results of the EACE will be reviewed to determine if the findings in this root cause are still valid. Corrective Action 29 will track this issue. The standing water posed no radiological concern because radiological releases through the CW B/D line had been terminated pending completion of this root cause report and completion of associated corrective actions.
Root Cause Report (RCR) 38237 Corrective Action to Prevent Recurrence (CAPR) revised the system walkdown inspection requirements, including specified frequency of walkdowns and documentation and reporting of walkdown results. RCR 38237 CAPR also replaced the vacuum breaker assembly with a surge-protected configuration.
Engineering has performed an effectiveness review of these actions (ATI 38237-10) and in the three years since the initial effectiveness review, there had been no major equipment failures, which leads to the conclusion -that the actions taken from the root cause report are effective in eliminating the possibility of large volume leakage due to major vacuum breaker failure.
20
 
Effectiveness of Braidwood Station response to radioactive leaks:
Interviews played an integral part in the determination of this root cause due to the lack of written information that was available from the Corrective Action Program (CAP) to this Root Cause Investigation Team for the Circulating Water (CW)
Blowdown (B/D) events. The fact that some spills were not captured in the Corrective Action Program is indicative of weak management review and oversight of spill response activities (Root Cause 4).
A potential root cause that was considered was that draft Commonwealth Edison procedure CSG-001, "General Action Plan For Response To Unmonitored Releases And Very Low Level Radioactivity Spills" was not implemented. This procedure contained guidance for mitigating intrusion of low-level radioactive spills into the groundwater. There was no reason found as to why the procedure was not implemented.
The failure to implement this procedure was not determined to be a root cause for three reasons. First, this procedure did not provide overall integrated guidance for spill evaluation and mitigation. Second, the reason the procedure was not implemented could not be identified.          Third, no corrective action to prevent recurrence could be determined.        Therefore, the lack of integrated procedural guidance to ensure proper recognition, evaluation and timely mitigation of the radiological spill events was considered a root cause (Root Cause 3) for the ineffective response to Circulating Water (CW) Blowdown (B/D) Vacuum Breaker (VB) leaks (CausalFactor3, Root Cause 3).
For example, in a number of events the station addressed the NPDES concerns but no Radiation Protection (RP) individuals were engaged to address radiological concerns. Additionally, when personnel with the requisite knowledge base were involved, the lack of a pre-engineered solution that could be executed was not available. This hampered response, as each step had to be created and reviewed before actions occurred. At the time of the 2000 spill, the final remediation steps were missed under these circumstances, as independent expert reviews/challenges did not occur.
21
 
Evaluation Methods used during the investigation process for the Root Cause.
RC Tool                  Why used                          Advantages                      Disadvantages overcome Event and Causal        Utilized due to the complexity    Provide an illustration of the  While time consuming, enlisted Factor Chart (Att 4)    of the issues and actions over    whole problem and              a full-time Root Cause person time.                              contributing factors,          for the skill/experience and Works very well with barrier  time large The  to create an E&CF number          Chart.
of events verge n a                ever, analysis, which became necessary during the            verged on a CCA. However, evaluation,                    one event was taken to represent them all and the analyses were completed utilizing that event (the 1998 event) as the template.
TapRoot                  Used to assign the cause codes    Consistent approach for more    Difficult to utilize and for individual causes of the      reliable cause coding.          understand categories.
event.                                                            Technique was used in conjunction with Trending/Coding procedure and Team input/brainstorming of causes.
Barrier Analysis (Att 2) Used extensively, as people,      Used to identify causal factors Utilized Team brainstorming to physical, and administrative      systematically, With the E&CF  assure all barriers were barriers should have prevented    chart and Cause & Effect        recognized.
the issue.                        analysis to identify process weaknesses. Supports proposed corrective actions.
Change Analysis          Team tried to utilize to evaluate  Made for a good starting point  Information contained in this (Att 5)                  changes in procedures and          in analysis of the E&CF chart,  attachment was inadequate to regulations.                                                      use effectively and was therefore not utilized as an input to this root cause report.
Cause and Effect        Found the "Why" Stair Case        This analysis method was key    Utilized E&CF chart and area Analysis (Att 3)        instrumental due to the large      in finding the common/root      experts in OPS, RP, Chemistry number of failed barriers,        cause used with barrier        - Environmental, and other analysis.                      stations as well as RA and Corporate to ensure entire background was understood for this complex problem.
Failure Modes and        Not Used                          Not Used                        Not Used Effects Analysis 22
 
Evaluation:
Cause (describe the cause and Po m identify whether it Problemis            a root cause or a Statement        contributing cause)  Basis for Cause Determination Unplanned        Causal Factor 1,
* Preventive Maintenance -The preventive maintenance program in year 2000 releases to the  Root Cause 1                had no requirement to perform any kind of internal valve inspection or ground from      The root cause              operational check and no requirement to periodically replace the valves. The unauthorized      of the large                vacuum breaker valves were essentially installed as runto failure components.
release paths. volume leaks in            There were no Technical Specification requirements or NRC commitments to 1998 and 2000 is            conduct periodic maintenance. Prior to 1999, walkdowns of the blowdown documented in                system were performed annually.
Root Cause Report (RCR)                In July l 999, a preventive maintenance template from STANDARD NES-G-08, 38237, which                CoinEd Performance Centered Maintenance (PCM) Templates, was adopted for determined that            application~to the vacuum breaker valves. The particular template chosen is the Circulating            specifically applicable to spring actuated safety relief valves, and contains no Water (CW)                  discussion of applicability to float type valves. The predefine task description is Blowdown                    "perform setpoint verification and seat leak check, or replace valve". The (B/D) Vacuum                periodicity was set at 10 years. The template chosen was the closest match from Breaker (VB)                all those available in the standard PCM template index.
Valves had inadequate                  . esign/Application -The barrier was challenged when system operation was D
preventative                changed without changing the design or configuration of the vacuum breaker maintenance                assemblies.
programs and inadequate                  Original CW blowdown system operation provided for controlling blowdown design                      flow using valves at the river screen house, thus the system would always configuration.              remain full of water. This method of operation was abandoned within the first two years of operation due to repetitive failures of the control valves. Operation thereafter provided for controlling blowdown flow using valves located in the plant near the main condensers and when flow is secured, the blowdown line would depressurize and partially drain resulting in a potential pressure surge when flow was reinitiated. Discussion with the valve manufacturer revealed that if the valves are subjected to significant pressure surges, they should be equipped with surge protection. The current configuration had no surge protection. The reason why the system operation was changed rather than correcting the material condition of the valves at the river screen house was not pursued since that decision was historical. Similarly, the reason the change was made without considering impact on the vacuum breaker design/configuration cannot be determined.
On January 16, 2006, a leak occurred on VB-7 due to failure of an internal guide bushing and was documented on IR 00442540. EACE 442540 is performing an evaluation of this failure. The results of the EACE will be reviewed to determine if the findings in this root cause are still valid. Corrective Action 29 will track this issue.
23
 
Cause (describe the cause and Problem    identify whether it is a root cause or a Statement  contributing cause)  Basis for Cause Determination Causal Factor 2,
* Although the corrective actions from the 38237 Root Cause Report were Root Cause 2                effective, the report did not address "small" spills because the need for a near The root cause              zero leakage standard was not k"own or suspected. The near zero leakage of the small                requirement was not identified in the 2000 Root Cause Report investigation due leaks, which                to a lack of technical rigor/questioning attitude. For details, refer to Attachment both preceded              12.
and succeeded the 1998 and 2000 leaks, was that the need for a near zero leakage standard was not identified, due to a lack of Technical Rigor/Questionin g Attitude.
Inadequate  Causal Factor 3,
* After this root cause was identified, it was analyzed to determine if it was response to Root Cause 3:              appropriate for this event. In other words, the team considered whether the unplanned  The first root              "why" question had been asked enough to adequately resolve the problem. The releases. cause for the              team attempted to ask "why" and there is no clear/concrete documentation to ineffective                explain why this 1990 procedure was not implemented (Failed Barrier, FB-4).
response was a              Utilizing TapRoot analysis process, the root cause is the most basic cause (or lack of                    causes) that can be reasonably identified that management has control to correct integrated                  and when corrected, will prevent (or significantly reduce the likelihood of) the procedural                  issue recurring. In this event, Braidwood Senior Management has the ability to guidance to                implement integrated procedural guidance to ensure thenecessary knowledge of ensure proper              local hydrology, the impact of low-level tritium leaks, and groundwater recognition,                regulations is directed to ensure consistent mitigation and remediation of future evaluation, and            events. Thus, it was concluded that the root cause statement met the criteria of timely mitigation          the TapRoot definition and it was appropriate for this event.
of the                  *  (Failed Barriers FB 1 -17) (See Attachment 2) CSG-001 1990 (draft only) radiological spill          contained guidance regarding underground transport mechanism for tritium and events.                    directions to remediate this pathway.          Procedures for responding to and assessing radiological spills are either non-existent or inadequate. There was limited guidance to acknowledge 35 IAC 620 requirements or subsurface transport mechanisms to provide dose to the public. Failed barriers 1-17 address lack of integrated procedural guidance to ensure proper evaluation of the event, including knowledge of local hydrology, the impact of low-level tritium leaks, and groundwater regulations. This procedure contained instructions for mitigating intrusion of low-level radioactive spills into the groundwater. The reason the procedure was not implemented, could not be identified. Because this procedure did not provide overall integrated guidance for spill evaluation and mitigation, the failure to implement the procedure was not considered a root cause.
Therefore, the lack of integrated procedural guidance to ensure proper recognition, evaluation and timely mitigation of the radiological spill events was considered a root cause (Root Cause 3) for the ineffective response to Circulating Water (CW) Blowdown (B/D) Vacuum Breaker (VB) leaks (Causal Factor3, Root Cause 3).
24
 
Cause      (describe the cause and Problem    identify whether it is a root cause or a Statement  contributing cause)  Basis for Cause Determination Inadequate  Causal Factor 4,          "    In review of the 2000 Issues Management Team notes and other available response to Root Cause 4.                  documentation, the ineffective response from both the station and corporate unplanned  A second root                  levels appears to have been due to a lack of clear delineation of specific releases. cause for the                  responsibilities during radiological spill response and remediation efforts.
ineffective                    Specifically, the interface of site and corporate Radiation Protection, Chemistry response was                    and Environmental departments are not clearly defined.
weak                      "    Due to the cross discipline teams needed to respond /document a low level management                      radioactive leak and the lack of one procedure to integrate the response, CAPR review and                      4 will ensure all aspects are covered.
oversight of spill response
* Original 2000 root cause (38237) was too narrowly focused.
activities.                "    The Issues Management Team actions had no accountability or tracking through the CAP process.
* Did not properly execute issue management procedures.
                                      "    Unaware of the 1991 State regulation regarding tritium limits.
A Senior Corporate Manager was chosen to assemble and direct the radiological remediation team. Four Corporate procedures which direct issues management were properly entered to identify, evaluate, remediate and communicate the radiological concerns. The four procedures include:
* NSP-RP-6101, "10 CFR 50.75(g)(1) Documentation Requirements"
* CWPI-NSP- I-I, "CAP Process Manual of Common Work PracticeInstructions
                                                - Instruction on Event Response Guidelines"
* OP-AA-101-501, "NGG Significant Event Reporting"
* OP-AA- 101-503, "NGG Issues Management".
However, no historical documentation could be located. to demonstrate that the procedures (other than NSP-RP-6101) were fully executed. This indicates weak execution of the spill remediation plan by the Issues Management Team and weak Braidwood Senior Management review and oversight of spill response activities. (Root
                                -Cause 4)
The water was pumped back into the B/D line on 11/10/00 and hydrology wells were installed in the area of the 2000 leak to characterize the local hydrology. Based on calculations and conclusions by a professional hydrologist, underground water in the area of VB-2 would take approximately 15 years to flow offsite. IDNS and EPA were informed. Further remediation efforts were not developed after the surface water was removed. Further efforts were limited to the mechanical failure oriented Root Cause Report (RCR) 38237 and the 10 CFR 50.75(g) characterization study. The 10 CFR 50.75(g) study did not sample groundwater for tritium, even though the NSP-RP-6101 procedure and the regulation clearly state to identify all radioisotopes (Failed Barrier 3). This procedure will be strengthened per CA 21. As a result, the groundwater tritium went undetected until the 2005 tritium sampling discovered the groundwater tritium.
This indicates weak Braidwood Senior Management review and oversight of spill response activities. (Root Cause 4)
See timeline for 2000 event, for further substantiation of needed improvements in Braidwood Senior Management oversight.
25
 
Cause (describe the cause and Problem          identify whether it is a root cause or a Statement        contributing cause)  Basis for Cause Determination Inadequate      Causal Factor 5,    Personnel were not aware of state regulations (35 IAC 620) to revise procedures and response to      contributing        training for these action levels. Additionally, those who would audit the ODCM/REMP unplanned        cause. Personnel    programs were also not aware that the regulatory and procedural deficiencies existed.
releases.        were not aware      (See Attachment 10) If the site had been aware of the requirement, then the site would of state            likely have been driven to properly evaluate groundwater.
regulations (example: 35 IAC 620)
Causal Factor 6,    (FB-30) Interviews with individuals indicated that notice to other Site Departments when Notification:        an event occurred did not always occur. This was also observed through a review of the Processes and        corrective actions database, which indicated that valve leakage was not always identified procedures for      in CAP. In the current corrective action process at Exelon, all issues whether communication        organizational or equipment related are entered and tracked in the corrective action not well defined,    program.
(FB-31) Interviews with individuals indicated that a process for formal notification to the sites of State regulation changes is lacking. This was also observed through a review of applicable regulations and the lack of those regulations being consistently addressed in the ODCM, Reportability Manual, and other applicable procedures.
Causal Factor 7,    Training does not exist for Operations, Chemistry or RP personnel for specific Training:            responsibilities related to radiological spill response and assessment (reference General training    Attachment 2) has no prompt to have personnel report environmental spills for assessment of radiological conditions.
Extent of Condition:
All Exelon Nuclear facilities are potentially affected, with added emphasis on Pressurized Water Reactors due to tritium production rates. A Nuclear Event Report (NER 428868-12) will require all Exelon Sites to take actions to research historical spills and determine if tritium remediation is required. The Nuclear Industry will be informed of the issue through a Nuclear Network Operating Experience Report (NNOE 428868-13). Other spill type (Hazardous Material) response procedures were reviewed and determined to have effective guidance through the Hazmat and Environmental programs (Attachments 2 & 8). These programs and procedures will receive further review and update to integrate radiological interfaces (CAPR 3).
26
 
Cause being addressed                                        Extent of Condition Review CF-I, RC-1,            This condition applies to any site using a similar configuration for blowdown and radioactive release CAPR-1: Significant    path. ATI 428868-13 was created to update the Nuclear Notification Operating Experience (NNOE) vacuum breaker leaks    to communicate this issue to the Nuclear Industry. ATI 428868-12 was created to update the (NER) in 1998 and 2000.      to communicate this issue to all Exelon sites. Issue Reports 00453379 and 00453387 document that Byron and LaSalle Stations have similar CW B/D and make up design configurations.
CF-2, RC-2,            This issue applies to all Exelon Nuclear Stations. All sites produce tritium. Pressurized Water CAPR-2: Continuing      Reactors produce a higher amount of tritium due to the usage of boron. ATI 428868-13 was created small vacuum breaker    to update the Nuclear Notification Operating Experience (NNOE) to communicate this issue to the leaks after the 2000    Nuclear Industry. ATI 428868-12 was created to update the Nuclear Event Report (NER) to event.                  communicate this issue to all Exelon sites. Issue Reports 00453379 and 00453387 document that Byron and LaSalle Stations have similar CW B/D and make up design configurations.
CF-3, RC-3,            This issue applies to all Exelon Nuclear Stations. All sites produce tritium that can possibly migrate CAPR-4 Procedures -    into groundwater. Pressurized Water Reactors produce a higher amount of tritium due to the usage of A lack of integrated    boron. ATI 428868-13 to update the Nuclear Notification Operating Experience (NNOE) to procedural guidance to  communicate this issue to the Nuclear Industry. ATI 428868-12 was created to update the Nuclear ensure proper          Event Report (NER) to communicate this issue to all Exelon sites.
recognition, evaluation, and timely mitigation of the spill events.
CF-4, RC-4,            This issue applies to all Exelon Nuclear Stations since the review and oversight is controlled by CAPR-3 & 5:            corporate procedures. Other spill type (Hazardous Material) response procedures were reviewed and Weak management        determined to have effective guidance for non radiological programs (Attachment 8). These review and oversight    programs and procedures will receive further review and update to integrate radiological interfaces.
of spill response      CAPR 3 (Human Performance) and CAPR 5 (Issues Management) address these issues for all sites.
activities.
CF-5, Regulations:      All sites have the potential for unplanned releases. The event at Braidwood station is one example.
Personnel were not      There are numerous other nuclear industry events (OPEX) that resulted in groundwater aware of State          contamination. For this reason, each site must assess the vulnerability of piping leaks and Regulations            contaminating groundwater. This assessment is not limited to those plants that make liquid discharges. The concern is leakage into groundwater - not dose from liquid effluents to a defined outfall release point. Which is to say, that the ODCM does not direct routine measurements for leakage locations that may produce an exposure pathway. Issue Reports 00453379 and 00453387 document that Byron and LaSalle Stations have similar CW B/D and make up design configurations.
Corrective Actions 5 through 14 will address this vulnerability at each site.
CF-6, Notification:    This issue applies to all Exelon stations. CAPR 4, CAPR 5, and CA-14 will address this Processes and            vulnerability at each site.
procedures for communication not well defined.
CF-7, Training:        This issue applies to all Exelon Nuclear Stations. ATI 428868-12 to update the Nuclear Event Report Personnel not all        (NER) to communicate this issue to all Exelon sites.
aware of concern with CW B/D piping and secondary side effluents being tritiated water.
CW B/D vacuum            Other Exelon/Amergen Nuclear sites were contacted to determine how those plants are configured breaker design          for circulating water blowdown and makeup and if they have experienced any similar problems with vacuum breaker float assembly failures. Byron and LaSalle stations were the only stations confirmed to have circulating water blowdown and makeup systems that utilize vacuum breakers in their design.
For circulating water blowdown and makeup systems, the extent of condition is limited to Byron and LaSalle. Reference Byron IR 453379 and LaSalle IR 453387 for the respective site OPEX review.
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Risk Assessment:
Plant-specific nuclear                                          Basis for Determination safety risk consequence None          There are no plant specific risks associated with this issue. There are no risks to the CW Blowdown system as a result of this issue, since the leaking (failed) vacuum breaker assembly would still function o prevent a vacuum from forming and causing damage to the CW Blowdown piping. This issue has no impact for core damage/accident mitigation. The event was reportable under Reportability Manual, SAF 1.9, News Release or Notification of Other Government Agencies.
Previous Events:
The only previous event in terms of Braidwood's response to a release of a contaminant to the nearby environment would be PIF A2000-02683, Oil in North Runoff, where waste oil from an oil separator overflow entered a ditch which formed the boundary between Braidwood Station and Godley on the Station's west side. However investigation of this event by Braidwood Station and Illinois EPA did not identify any contamination of surface or groundwater in Godley. This event is listed in the table below as part of the discussion of events found in the search of the INPO web site.
Braidwood has identified 17 leaks from the Circulating Water Blowdown piping, and three of the events, 1996, 1998, and 2000, resulted in flooding of local areas. The previous events table contains a summary of leaks identified from records in the Corrective Action Program and the Work Control Process, including the Station's response. The majority of the blowdown leaks were small (as described in Table 1) and the water does not appear to have overflowed out of the vacuum breaker vault. However, to verify this, wells were drilled in the area of each of the Vacuum Breakers and tritium samples analyzed. The areas around VB-1, VB-2, VB-3, VB-4 and VB-7 have been verified to contain tritium. The entire length of the CW blowdown line has been tested for integrity and found to be intact, with no leaks above the minimum detection limit of 1.0 gpm.
The INPO website was searched for Operating Experience (OPEX) using the terms tritium, release, offsite, and groundwater. Passport was also searched using similar parameters.
There have been numerous events concerning unplanned releases to the environment at numerous sites. For the most part, the descriptions of the, events do not discuss remediation or continuing monitoring, but rather a statement that no activity was released from the site or detected offsite.
One instance (Pickering, 1997) was found where the licensee attempted to remediate the tritium in the groundwater by flushing the ground with fire protection water. This did not reduce the tritium concentration in the groundwater. Only one event (Waterford, 2003) reported detectable increases in offsite tritium due to a primary to secondary tube leak.
The 2000 overflow of a Braidwood oil separator was included because of its relevance in terms of potential impact to the public and station response.
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Operating Experience (OPEX) reports were reviewed. The OPEX reviewed did not reveal any missed opportunities to have prevented the events in this root cause report.
Braidwood Station had no known active leaks and had no increases in any routine radiological environmental samples when low level groundwater radioactivity due to tritium was discovered.
The following are summaries of relevant OPEX events in chronological order:
Previous Events                                        Previous Event Review INPO Oyster Creek, 1-20-81      Condensate storage and radwaste transfer piping leaks resulted in underground release of radioactive liquid. No remediation was performed.
SER 4-81 Hatch, 12-3-86, OE1905,    124,500 gal from a spent fuel pool leak went into the storm drain system and eventually Operating Plant            reached a swamp area within the owner-controlled property. The water discharge resulted Experience                from a loss of air to the inflatable seals used in the transfer canal between the Units 1 and 2 Spent Fuel Pools. The area was decontaminated, and no activity was detected outside Georgia Power property.
Prairie Island, 5-1-92,    Elevated levels of tritium (concentrations of 1, 300 to 1,500 pCi/L) were detected in an PNO3-92-023, Elevated      onsite groundwater well. Offsite wells sampled showed no increase in-levels of tritium.
levels of tritium detected No further details or follow up actions have been issued on this Preliminary Notification in onsite well            of Occurrence.
Dresden, 10-19-94,        Degraded cathodic protection system and breached wrapping of underground piping OE7067, Cathodic          results in through-floor pitting in both contaminated condensate storage tanks and three Protection System          radwaste tanks between 1992 and 1994, through-wall pitting on the HPCI test return line Degeneration              and a demineralized water line, and underground fire protection piping degraded in several areas. The leakage was characterized and a remediation plan to monitor the tritium plume was implemented. No documented review of OE 7067 could be found for Braidwood Station.
Pickering A, 7-18-97,      Since 1979, groundwater at the upgrader plant Pickering A (UPP-A) has had tritium levels SER PD97184, Elevated      in the surrounding groundwater that are above background. Several attempts have been Concentrations of Tritium  made to reduce the tritium concentrations in the groundwater including pumping in Groundwater            groundwater with low levels of tritium to the lake and flushing the area with fire protection water. Tritium concentrations in groundwater, however, remained constant.
Increased tritium is due to spills and unplanned releases and not taking appropriate action to remediate the area after spills or discharges.
Braidwood, 6-25-00, PIF    Oil separator #1 overflowed into the north runoff and offsite. Root Causes were A2000-02683, Oil in        inadequate preventative maintenance of the north runoff ditch and the oil separator.
North Runoff              Remediation and offsite sampling was performed to mitigate and assess the impact to the public.
Limerick, 2-18-02, Event  Tritium concentrations of 10000 pCi/L were detected in the normal waste holding pond.
Number 352-020215-1,      There was no plant impact, no personnel exposure, and no release above regulatory limits Tritium Identified in      to the environment. Groundwater monitoring is not performed.
Normal Waste Water Holding Pond and Auxiliary Boilers 29
 
I    Previous Events Previous Event Review Prevous vens                                    Prviou Evnt Rvie Salem, 9-18-02,          Leakage from the Unit 1 Spent Fuel Pool as a result of clogged telltale drains was found.
OE15788, Spent Fuel      To determine the affect of the leakage on site groundwater, 8 monitoring wells were Pool Leakage, and        installed as reported on 3-19-03. Tritium results were as high as 69,200 pCi/L in one OE15859 Tritium          sample, and positive results were found in 4 other wells. As reported on 7-25-03, sample Detected in Groundwater  results obtained from new wells indicate tritium concentrations of 3.5M pCi/L and 125K Samples from Onsite      pCi/L. Gamma scans of samples from both locations detected no other radionuclides.
Monitoring Wells        There is no indication of any offsite release and there is no threat to the public or company (Follow-up to OE15788)  employees. On 5-3-04, NRC Information Notice 2004-05: Spent Fuel Pool Leakage To Onsite Groundwater is issued describing the Salem event. Braidwood Station does not have any reasonable release paths from our spent fuel pool to the groundwater. The NER issued by Braidwood requires evaluation of all potential tritium spill paths.
Waterford, 2-28-03,      Primary to secondary leakage from steam generator tube/tube plug degradation resulted in OE15894, Substantial    an increase in secondary tritium levels and approached a reporting limit listed in the Rising Trend in Tritium  Technical Requirements Manual (TRM) for a local drainage canal.
Activity Measured at (REMP) Sample Location at Waterford Dresden, 7-31-04,        HPCI suction line had been leaking since Nov 2003. Up to 6M pCi/L was detected in CR248494, High Tritium  monitoring wells and stormdrains on site. Hydrology study shows the event does not Activity In Onsite Wells affect residential wells near the site. Routine monitoring established for 1994 event had and Storm Drains        been discontinued. Remediation consists of quarterly monitoring of plume as it dissipates, verifying it does not migrate off site.
Braidwood, 12-8-04,      Site approaches ODCM quarterly dose limits of 7.5 mrem/unit following the AlR1 I OE19305 / OE19623,      refueling outage due to failed fuel conditions. The cause of challenging the offsite dose Station Challenges      limit is that the effluent release procedures and processes did not have limits or controls in Effluent Quarterly Dose  place to account for failed fuel conditions.
Limits During Unit 1 Outage Watts Bar, 2-8-05,      550,000 pCi/L discovered during routine onsite environmental monitoring. No tritium has OE20318, Onsite          been detected in water samples from offsite monitoring locations, public drinking Groundwater Tritium      supplies, or the Tennessee River. Source is from a Cooling Tower Blowdown Line or Above Reporting Limits  previous leakage from a temporary effluent line.
Indian Point, 9-1-05,    Hairline cracks in the liner of the Unit 2 spent fuel pool are found. On 10-5-05 (Event OE21506 Spent Fuel Pool  Report 42014), 21100 pCi/L of tritium was detected in monitoring well MW-111 located Hairline Crack          in the Indian Point 2 transformer yard. Other wells showed negative. The sampling that was done was part of an ongoing investigation to verify and quantify previously identified leakage, potentially from the spent fuel pool. Continued sampling discovered tritium in 6 of 9 onsite wells.
Haddam Neck, 10-31-05,  Spent Fuel Pool leakage to the site groundwater was discovered when removing soil east Event 42099              of the Spent Fuel Building. The quantity of water leaked is unknown. Estimates based on historic Spent Fuel Pool evaporation data indicate that the leak was small - on the order of a few gallons per day. Based on readings from down-gradient monitoring wells, there is no travel offsite.
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Previous Events                                      Previous Event Review EVENTS IDENTIFIED          Description and review of event.
AT BRAIDWOOD STATION 12-5 A1998-04324,    AR written Monday after Southern Div. PR contacted by neighbor. They sighted leaking CW Blowdown Vacuum        vacuum breaker from the south was unaware of the "pond" to the north: Chemistry Breaker Leak - pond of    contacted environmental services. AR status changed to B I due to possibly exceeding water found on property,  release permit limits. This incident was initiated when (name removed) was contacted with standing water in    about the pooled water by a local resident. (Name removed) and (name removed) road ditch along Smiley    investigated and noted the pool was located on station property. There was minor Rd.                        puddling in the adjacent ditch but this water did not run off. Environmental services were consulted and since the ponded area was restricted to station property there was no NPDES concern. The blowdown system was shut down to isolate the vacuum breaker and stop the leakage. WR 980127749 was written to repair the vacuum breaker. The work was performed over the weekend of 12/5. The station response to this event was excellent. Maintenance had this repaired in -24 hrs. This failure had prevented the station from performing liquid releases.
11-7 A2000-04281,    The valve had been in this condition for an unknown period of time, most likely several Failed Circulating Water  days. The ground in the nearby area is sandy and drains quickly. The ground was Blowdown Vacuum          saturated with water. Upon the discovery of the leak operations isolated CW blowdown Breaker Caused            on the afternoon of 11/6/2000. Draining of the piping to affect the repairs was started on Unplanned Flooding        the morning of 11/7/2000. The 0CW135 (manual isolation to 0CW136) and the 0CW136 Outside the Power Block - CW blowdown vacuum breaker valve were replaced with new valves by 1600 hrs 0CW136 CW blowdown        1 1/7/2000. Once a year a visual inspection of the blowdown and make up lines is valve was found leaking  performed, including the vacuum breakers. The float in question is an internal part and past its main seat.      cannot be inspected without disassembly of the valve. A degraded condition could be found by noting some leakage past the valve seats. This is the first failure of this type. A schedule of replacements will be proposed to the PHC by the system engineer to prevent reoccurrence. Extent Of Condition: the same/similar valve is used in several places on the CW make up and blowdown piping. Byron has a CW makeup and blowdown pipe, however it is not known if Byron has vacuum breakers and if so what type of vacuum breakers. A message was left for the Byron CW system engineer about this problem.
11-17 A2000-04389    The station's response to a December 1998 CW vacuum breaker valve (OCW060) failure (39223), Inadequate      appears to have been inadequate. No evidence can be found to documenting any follow-response to 1998 CW      up sampling, surveys or reporting requirements. PIF# A 1998-04324 details the station' vacuum breaker valve,    response to the 1998 leak. This issue was discovered during the present root cause leak.                    investigation for the CW vacuum breaker valve failure (OCWI136).
11-30 A2000-04465,  Station was slow to implement event response guidelines, CWPI-NSP-AP-1-1, or NGG Slow response to          Issues Management, OP-AA-101-503, for the CW blowdown vacuum breaker failure that implementing Event        was discovered on 11/06/00. NGG Issues Management was not entered until 2+ days Response                  after discovery of the valve failure when rad sample results indicated detectible levels of Guidelines/NGG Issues    particulate radioactivity from the spill.
Management procedure.
6-18 A2001-01806,    Unauthorized Release Path? [#3 & 11 ]- OCW060 was found seeping water from between CW B/D Valve Leaking. the vacuum breakerfloat and the Buna-N seal. Leakage appears to be about I gal/2 hours.
As discovered during the investigation of CR# A2000-04281, periodic maintenance of the circulating water blowdown vacuum breaker valves had not previously been up to the standards desired by the station. A campaign was initiated in Q2 2001 to repair/replace as necessary these vacuum breaker valves. When the vaults were opened, four were discovered to contain water (vaults housing OCW060, 0CW144, 0CW075 and 0CW078).
Radiological analysis of the water revealed 2 of the 4 vaults with radioactive material present in the water (OCW060 and 0CW078 showed activity).
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Previous Events                                          Previous Event Review 7-9 A2001-02016      A review of a root cause report titled "Circulating Water Blowdown Line Vacuum (56710), Weaknesses      Breaker Failure Due To Low Stress, High Cycle Fatigue, Resulting In Flooding Of Owner Identified in            Controlled Property And Discharge Outside Of NPDES Approved Path" determined that Documentation of RCR      there were weaknesses associated with the report documentation (reference CR# A2000-For CW Blowdown          04281 .and ATI# 38237). Although the report was well written, the review identified that Valves.                  the description of the Corrective Actions to PreventRecurrence (CAPRS) lacked the clarity needed for mechanical maintenance to understand the full scope of work required to execute the CAPR. Furthermore, it appears that scheduling issues were not fully considered when the due dates were set.
5-4 106767, Small    OCW060, CW blowdown vacuum breaker, was identified as having seepage from the vent leak identified from      on the air release valve, (air release valve is part of the entire vacuum breaker assembly OCW060 blowdown valve    but sits adjacent to the main vacuum breaker valve). Main vacuum breaker valve assembly (VB-3)          appeared satisfactory, no leakage. Water level in pit was 30" from top of manhole. No evidence of leakage outside of the manhole was noticed. Water in manhole/pit appears to be a normal condition associated with groundwater infiltration into the manhole.
8-20 172376, CW      Main vacuum breaker seat has 1 gpm leak. Water is draining to vacuum breaker pit only Blowdown Vacuum          no area flooding is occurring.
Breaker 0CW138 has 1 gpm leak (VB-4) 8-27 173204,        Modification testing associated with EC336241 was performed on 8/25/03. The testing OWX26T release with      required a release to be performed from the OWX26T release tank while blowdown flow suspected leakage from    was established at -25,000 gpm. Seat leakage from the 0CW138 blowdown vacuum OCW138 VB-4.              breaker most likely occurred during the time that blowdown flow was at a flow rate of 25,000 gpm. Based on field observations performed on 8/21/03 and 8/27/03 the suspected leakage from the OCW 138 during the time of the OWX26T release was between .25 and 1 gpm, (Note: 0WS26T release occurred between 0630 and 0710 on 8/25/03, Release package L03-104.) Field observations of the 0CW138 were also performed at blowdown flow rates of between 12,000 & 14,000 gpm. These observations indicate that no leakage occurs at these lower flow rates and that the vacuum breaker appears to be open, (Note:
OCW138 open with no leakage indicates that the blowdown pipe is not completely full at the lower flow rates.)
8-29 173688, Water  While performing the annual vacuum breaker surveillance we discovered water in the pit in Vacuum Breaker Pit for containing breaker OCW060. WR # 00110407 was initiated.
breaker OCW060 [#3].
9-11 175241,        When CW blowdown was increased per BwOP CW- 12 (to approximately 22,000 gpm, 0CM138 leaking at high    0CW138 was discovered to be leaking at 5 drops per minute.
CW blowdown flow rates
[#4].
11-17 274328,        While performing OBwOS CW-A1 (CW System B/D and M/U Vacuum Breaker Vacuum Breaker            Inspection) vacuum breaker 0CW069 was popping/leaking. The leakage was small and 0CW069 Is Leaking [#8]. contained within the vacuum breaker's valve pit. Per the Limitations and Actions of the procedure the Shift Manager and RP were notified immediately. Chemistry was notified of the potential for exceeding a limit for NPDES. System Engineering was contacted for guidance and it was determined that the 0CW068 valve would be maintained closed to isolate the vacuum breaker leakage. The System Engineer recommended that two adjacent vacuum breakers not be isolated with CW blowdown in operation. EST (37096)
(Equipment status tag) was generated to document the abnormal position.
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Previous Events                                        Previous Event Review 4-25 328451, Tritium Two samples results from onsite property located on the downstream side of the culvert at Indicated In Samples      the old A entrance gate came back from the vendor with tritium indicated on the results.
Taken From Onsite        Specifically, the analysis results from Environmental Inc. Midwest Laboratory (EIML)
Culvert.                  indicated results of 539 +/-121 pCi/L tritium (sampled on 03/24/05) and 582.963 +/-
112.314 pCi/L tritium (sampled on 04/07/05).
5-18 336401, CW      CW BD Vacuum breaker 0CW058 pilot valve leaking 20 DPM. Need WR to repair.
BD Vacuum Breaker 0CW058 Pilot Valve Leaking 20 DPM [#1].
5-24 338111,        While performing ER-BR-400-101, OCW 140 blowdown vacuum breaker valve was OCW140 Blowdown          observed to have continuous seepage of water from the valve float/seat area. The leakage Vacuum Breaker Valve      is small enough to be contained within the vacuum breaker valve pit with approximately Leaking From Seat [#6. one foot of standing water in the pit.
9-8 371248, NRC      During NRC debrief on 8/31/05, there was discussion regarding the CW blowdown Questions On Previous    vacuum breaker, 0CW058, leakage that was identified in May 2005 (Reference IR Actions With CW B/D      336401). A previous root cause was performed for vacuum breaker failures that occurred vacuum breakers.          in 2000. The NRC question is: Subsequent to 0CW058 leakage identified in May 2005, were the root cause actions reviewed for adequacy? If so, what was the conclusion?
11-30 428868,        Elevated levels of tritium have recently been identified in certain onsite groundwater Elevated Tritium Levels  sampling wells. The exact source has not been located nor has the source been In Onsite Monitoring      determined to be active or historical.
Wells.
NOTE: Review was revalidated on 02/16/06 with no new relevant events found.
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Corrective Actions to Prevent Recurrence (CAPRs):
Root Cause Being            Corrective Action to Prevent Recurrence                Owner          Due Date Addressed                    (CAPR)
Causal Factor 1, Root        (CAPR 1: ATI# 38237-08, 38237-17, & 38237-18)          A8930I"        Completed Cause 1: The root cause      Institute a Preventative Maintenance Program and                        03/01/01 of the significant leaks in  system modifications, which are complete and have 1998 and 2000 is            been verified to be effective in preventing major valve documented in Root          failures that result in large volume spills.
Cause Report (RCR) 38237, which determined    [NOTE: On January 15, 2006, a leak occurred on VB-that the Circulating Water  7 due to failure of an internal guide and was (CW) Blowdown (B/D)          documented on IR# 442540. (See analysis section of Vacuum Breaker (VB)          how this issue is addressed) CA-29 will review EACE Valves had inadequate        442540 to ensure corrective actions from 2000 RCR preventative maintenance    38237 & RCR 428868 are still effective.]
programs and inadequate design configuration.        Braidwood Station presently performs daily walkdowns of the blowdown vacuum breakers to verify Failed Barrier (FB- 20)      that no leakage is occurring.
Piping/Valves equipment failures Causal Factor 2, Root        (CAPR 2)                                                1) A8901H3      1) 04/03/06 Cause 2: The root cause      1) The Braidwood Tritium Remediation Team will of the small leaks, which    determine the methodology and implement the plan for both preceded and            future radiological releases, including leakage succeeded the 1998 and      standards. (Note: AR 435383) 2000 leaks, was that the need for a near zero        (CAPR 3)                                                2) A8923 and    2) Completed.
leakage standard was not    2) HU-AA- 102 and HU-AA- 1212, Technical Human          A8961 (approved (Approved for identified, due to a lack of Performance Practices and Technical Task Risk/Rigor    for use at      use at Technical                    Assessment, Pre-Job Brief, Independent Third Party      Braidwood)      Braidwood in Rigor/Questioning            Review, and Post-Job Brief procedures have been                        07/09/04 and Attitude.                    instituted to improve technical rigor, questioning                      07/14/04) attitude, and attention to detail.
CF-5 Regulations/Oversight FB-33 Weak management review and oversight of spill response activities.
34
 
Root Cause Being          Corrective Action to Prevent Recurrence.                Owner          Due Date Addressed                  (CAPR)                                                  OwnerDueDat Causal Factor 3, Root      (CAPR 4)                                                NCS            6/20/06 Cause 3:                  Develop and implement Standard Exelon procedures to      A8015ENV The first root cause for  provide integrated and detailed spill and leak response the ineffective response  requirements to ensure full compliance with State and was a lack of integrated . Federal laws and regulations and integrate Exelon procedural guidance to    resources to respond to radiological leaks and spills.
ensure proper recognition, evaluation, and timely mitigation of the radiological spill events.
CF-3 Procedures Failed Barrier (FB)-l BwAP 750-4 FB-2 BwAP1 100-16 FB-3 NSP-RP-6101 FB-4 RP-AA (no specific procedure)
FB-6 BwOA ( no specific procedure FB-12 ER-BR-400-101 FB-13 OBwOS CW-A1 FB-14 EN-AA Causal Factor 6 Notification FB-30 Notification to other site departments Causal Factor 4, Root      (CAPR 3)                                                1) A8923 and    1) Completed Cause 4. A second root    1) HU-AA-102 and - HU-AA-1212, Technical Human          A8961 (approved (Approved for cause for the ineffective  Performance Practices and Technical Task Risk/Rigor      for use at      use at response was weak          Assessment, Pre-Job Brief, Independent Third Party      Braidwood)      Braidwood in management review and      Review, and Post-Job Brief procedures have been                          07/09/04 and oversight of spill        instituted to improve technical rigor, questioning                      07/14/04.
response activities,      attitude, and attention to detail.
(CAPR's 3 and 5)
(CAPR 5)                                                2) A8016NGGOP  2) 04/21/06 CF-5                      2) OP-AA-106-101-1002, Exelon Nuclear Issues Regulations/Oversight      Management, will be revised to: 1) improve Corrective FB-33 Weak management      Action Program (CAP) controls of Issues Management review and oversight of    teams, 2) utilize the tools and techniques of the Exelon spill response activities. HU-AA-102 and HU-AA-1212, Technical Human Performance Practices and Technical Task Risk/Rigor Assessment, Pre-Job Brief, Independent Third Party Review, and Post-Job Brief procedures, 3) strengthen reporting requirements to affected station Senior Management, and 4) define affected station Senior Management responsibilities for oversight and challenge of events and issues from initial identification to final disposition.
35
 
Effectiveness Reviews (EFRs):
Effectiveness CAPR / CA being addressed                                Review Action          Owner    Due Date Causal Factor 1, Root Cause 1: The root cause of the    (EFR 1: 00038237-10)    A8930Tr  Completed significant leaks in 1998 and 2000 is documented in      Perform effectiveness            05/22/2002 Root Cause Report (RCR) 38237, which determined          review of CAPR's under that the Circulating Water (CW) Blowdown (B/D)          ATI# 00038237-Vacuum Breaker (VB) Valves had inadequate                7,8,10,17-20 preventative maintenance programs and inadequate design configuration.
EFR assignment for CAPRs # 2, 3, 4, & 5:                EFR 2                  A8932CHEM 6/20/07 (CAPR 2) The Braidwood Tritium Remediation Team          Perform effectiveness will determine the methodology and implement the        review of CAPR(s) under plan for future radiological releases, including leakage ATI#428868 for CAPR#
standards.                                              2,3,4,5 (CAPR 3) HU-AA-102 and HU-AA-1212, Technical Human Performance Practices and Technical Task Risk/Rigor Assessment, Pre-Job Brief, Independent Third Party Review, and Post-Job Brief procedures have been instituted to improve technical rigor, questioning attitude, and attention to detail.
(CAPR 4) Develop and implement Standard Exelon procedures to provide integrated and detailed radiological spill and leak response requirements to ensure full compliance with state and federal laws and regulations and integrate Exelon resources to respond to radiological leaks and spills.
(CAPR 5) OP-AA-106-101-1002, Exelon Nuclear Issues Management, will be revised to: 1) improve Corrective Action Program (CAP) controls of Issues Management teams, 2) utilize the tools and techniques of the Exelon HU-AA- 102 and HU-AA- 1212, Technical Human Performance Practices and Technical Task Risk/Rigor Assessment, Pre-Job Brief, Independent Third Party Review, and Post-Job Brief procedures, 3) strengthen reporting requirements to affected station Senior Management, and 4) define affected station Senior Management responsibilities for oversight and challenge of events and issues from initial identification to final disposition.
MRC assignment for EFR                                    CA-1                    A8932CHEM 6/27/07 Present the EFR to MRC.
36
 
Corrective Actions:
Cause Being Addressed              Corrective Action (CA) or Action item (ACIT)                Owner    Due Date Causal Factor 5        CA-2                                                        A8961    08/30/06 Regulations/Oversight  Develop a case study of this event. Provide initial and Failed Barrier (FB-33) continuing training for appropriate Braidwood Station and Weak management        Exelon Corporate Management personnel.
review and oversight of radiological spill  CA-3                                                        A8961    07/21/06 response activities. Generate a training request for Dynamic Learning Activity (DLA) for all Braidwood Duty Team personnel using 2000 release conditions and revised response and reporting procedures implemented in CAPR4. Create additional assignments as warranted. Report training request action determinations to STC.
CA-4                                                        NCS      05/29/06 Generate a training request to review other potential leaks A8076CHEM beyond tritium to address extent of condition regarding Exelon management's control of hazardous material spills.
If deficiencies are noted, write IR's to have those deficiencies addressed. Report training request action determinations to STC.
Causal Factor 5.      CA-5                                                        NCS      05/29/06 Regulations/ Oversight Revise the Midwest ODCM and/or program procedures to        A8076CHEM FB-27 Title 35 IAC    incorporate the State of IL requirement of <20,000 pCi/L part 620 groundwater  of tritium for groundwater (35 IAC 620.410.e).3)) and the quality                State of IL requirement for non-degradation (35 IAC 620.301.a))
CA-6                                                        NCS      05/29/06 Revise the ODCM and/or program procedures as                A8076CHEM warranted to incorporate the State of PA requirements for radioactivity in groundwater.
CA-7                                                        NCS      05/29/06 Revise the ODCM and/or program procedures as                A8076CHEM warranted to incorporate the State of NJ requirements for radioactivity in-groundwater CA- 8                                                      NCS      05/29/06 Clearly define to each station (extent of condition), the  A8076CHEM changes to the ODCM based on review of Illinois laws governing radioactive contamination of groundwater (potable water). Assign additional corrective actions to ensure site's ODCM reflects and implements applicable regulations.
CA-9                                                        NCS      05/29/06 Clearly define to each station (extent of condition), the  A8076CBEM changes to the ODCM based on review of Pennsylvania laws governing radioactive contamination of groundwater (potable water). Assign additional corrective actions to ensure site's ODCM reflects and implements applicable regulations.
37
 
Cause Being Addressed              Corrective Action (CA) or Action item (ACIT)              Owner    Due Date Causal Factor 5.        CA-10                                                    NCS      05/29/06 Regulations/ Oversight  Clearly define to each station (extent of condition), the A8076CHEM Failed Barrier (FB)-27  changes to the ODCM based on review of New Jersey Title 35 IAC part 620  laws governing radioactive contamination of groundwater groundwater quality    (potable water). Assign additional corrective actions to ensure site's ODCM reflects and implements applicable regulations.
Causal Factor 3,        CA- 1                                                    NCS      05/29/06 Procedures            Corporate Regulatory Assurance to perform an extent of    A8002RAPO condition review regarding ODCM, REMP, RETS and FB-7 LS-AA-1020 &      state regulations for needed changes to the Reportability 1110 Reportability    Manual and create additional actions as required.
Manual CA-12                                                      NCS      4/14/06 FB-8 LS-AA-1020 &      Corporate Regulatory Assurance to revise the              A8002RAPO 1110 Reportability    Reportability Manual for reporting requirements of 35 Manual                IAC 611/620 Groundwater Tritium Release Path, 20,000 pCi/L limitations, and Illinois SB241 Community Right to FB-9 LS-AA-1020 &      Know requirements.
1110 Reportability Manual Causal Factor 5,      CA- 13                                                    NCS      06/28/06 Regulations/ Oversight Revise CY-AA-170-000 and associated procedures to          A8076CHEM require audits of the ODCM against applicable laws and FB-28 Corporate        regulations at.an acceptable frequency. Review the need Oversight              for revision to include State regulations into Step 4.2.1 basis of the ODCM. Create additional actions as warranted.
Causal Factor 3,      CA-14                                                      NCS      4/14/06 Procedures            Review the process by which the company becomes aware      A8015 ENV FB-1 1 LS-AA-1020 &    of new environmental laws and regulations for 1110 Reportability    radiological and non-radiological issues and how they are Manual                integrated and communicated into company policies, programs, and procedures. Assign additional actions as necessary, if process changes are needed.
Causal Factor 5, Regulations/Oversight FB-26 Title 35 IAC part 611 groundwater quality FB-27 Title 35 IAC part 620 groundwater quality Causal Factor 6, Notification FB-31 Notice to sites of new State Regulations 38
 
Programmatic/Organizational Issues:
Programmatic and Organizational              Corrective Action (CA) or Action Item (ACIT)              Owner    Due Date Weaknesses Causal Factor 5,            CA 15                                                    NCS      5115/06 Regulations/Oversight      Evaluate the groundwater and food crop pathway per        A8076CHEM ODCM Table 12.5-1 Section 3.a note (6). Assign Failed Barrier (FB)-24      additional actions as necessary, if the pathway is ODCM requires              credible.
evaluation of groundwater pathway if      CA 16                                                    NCS      5/15/06 credible                    Revise the Site specific portions of the ODCM to          A8076CHEM incorporate the new monitoring wells as determined by FB-25 ODCM requires        the ODCM Environmental Specialist to be credible evaluation of              groundwater (well water) monitoring sources into the groundwater pathway if      ODCM Table 11-1 Section 3.a note (6) and ODCM credible                    REMP Table 12.5-1 Section 3a Note (6).
Causal Factor 7, Training  CA 17                                                    A8931RP  3/14/06 Generate TR to develop appropriate training for the RP FB-21 Certification of      management and technician level of knowledge Chemistry personnel        regarding the CW B/D system and the radioactivity expected to be present. Refer to the Root Cause Report FB-22 Licensed and          to be used as a case study. If the TR is rejected, report Non-licensed Operator      out to Senior Training Council (STC).
initial and requalification CA 18                                                    A8932CHEM 3/14/06 training                    Generate TR to develop appropriate training for the chemistry management and technician level of FB-23 Certification of      knowledge regarding the CW B/D system and the RP/HP                      radioactivity expected to be present. Refer to the Root Cause Report to be used as a case study. If the TR is rejected, report out to Senior Training Council (STC).
CA 19                                                    A8910OPS  3/14/06 Generate TR to develop appropriate training for the operations personnel level of knowledge regarding the CW B/D system and the radioactivity expected to be present. Refer to the Root Cause Report to be used as a case study. If the TR is rejected, report out to Senior Training Council (STC).
Causal Factor 3,            CA 20                                                    A8910OPS  5/29/06 Procedures                  Ops to add precautions to BwOP CW-12, BwOP WX 526TI, & BwOP WX-501TI for release shutdown on FB-15 BwOP CW-12            leak to environment and for the release restrictions FB-16 BwOP WX-526T1        dealing with Reportability Manual Section RAD 1.21 FB-17 BwOP WX-501T1        (i.e.: 100 Ci. limit on tritium releases over a 24 hour period).
Causal Factor 3            CA 21                                                    A8931RP  6/1/06 Procedures:                RP manager to present to peer group changes to FB-3, NSP-RP-6101,          50.75(g) procedure to clearly address actions necessary "10 CFR 50.75(g)(1)        for tritiated water spills, including evaluation for dose Documentation              assessment to the public and initiate follow-up actions Requirements"              as appropriate to track necessary procedure changes.
39
 
OTHER ISSUES:
Other Issues Identified During the Investigation            Corrective Action (CA) or Action Item (ACIT)              Owner    Due Date Other issues: Alarms/    CA-22                                                    A8930TT  03/24/06 Annunciators            Braidwood System Engineering to review operation of        IR435383 the CW. blowdown system and determine the optimum Failed Barrier (FB)-I 8  monitoring scope and frequency of inspection PM's Leak detection of        and walk downs for the System. If applicable, identify vacuum breakers          gaps and create additional ATI's as required.
Other issues:          CA-23                                                      A8930TI  07/14/06 Alarms/Annunciators      Braidwood System Engineering to research and              IR435383 evaluate passive vacuum breaker replacement options FB&#xfd;18 Leak detection of  and present findings to PHC for approval if the CW vacuum breakers          Blowdown system will be used for radwaste releases in the future. If no action is taken, present this fact to MRC.
Other issues: Alarms/    CA-24                                                      A8930TT  07/14/06 Annunciators            System Engineering to work with Design Engineering        IR435383 to research and evaluate viable remote monitoring FB-19 Alarms and        instrumentation systems that can detect lower level Annunciators            external leakage from the blowdown system and automatically notify Braidwood Operations if the CW blowdown system will be used for radiological releases. If no action is taken, present this fact to MRC.
Other issues: Work      CA-25                                                      A8931RP  3/10/06 Orders:                  RP to provide information to Work Planning so that a work standard can be created for work activities that FB-32                    involve potentially tritiated water. This information Model PM work orders    will be used to update PM model work orders and and current work orders  current work orders involving potentially tritiated for B/D vacuum          water.
breakers Causal Factor 3          CA-26                                                      NCS      5/29/06 Procedures              Corporate Work Control to implement revision of WC-        A8035OUT AA- 106 to incorporate a higher work priority for FB-5                    response to unplanned low-level radioactive water WC-AA-106                being released to the environment and repairs to Attachment I implies a  release path monitors.
"B2" if increased sampling Other issues: Work      CA-27                                                      A8925PLN 4/10/06 Orders                  Using the information provided by RP, create a work standard to be used for work activities that involve FB-32 Model PM work      potentially tritiated water and update PM model work orders and current work  orders and current work orders involving potentially orders for B/D vacuum    tritiated water (RWP, sample for tritium, instructions breakers                for pumping tritiated water).
40 C-
 
Other Issues Identified During the Investigation              Corrective Action (CA) or Action Item (ACIT)              Owner    Due Date Causal Factor 6,          ACIT-28                                                    A8921NOA 03/28/06 Notification              Discuss this RCR with the Corporate NOS Peer Group to evaluate changing the NOS auditing template Failed Barrier (FB)-29    standard for the ODCM Program. Document results NOS Audit NOSA-          and assign additional actions as required.
BRW-05-08 (AR 287718) November 22, 2005 Causal Factor 1, Root    CA-29                                                      A8930T"  03/28/06 Cause 1                  Review EACE 00442540 to ensure corrective actions from 2000 RCR 38237 & RCR 428868 are still effective Causal Factor 3,          CA-30                                                      A8931RP  11/28/06 Procedures                Review 50.75(g) files to ensure tritium and or any other isotopes are included for all blowdown vacuum FB-3 NSP-RP-6101          breaker water events and perform 50.75(g) evaluation for all blowdown vacuum breakers not previously completed.
Other issues: Procedures  CA-31                                                      A8930TT  Per CA BwOP CW-12 was revised to undo water hammer                        process FB-20 Piping/valves      corrective actions from the 2000 root cause report.
equipment failures        Issue to be addressed under IR 45338 1.
01 fl, ODCM              IR 453638 Tritium Remediation Team review the              A8901H3  4/01/06 Reportability review for  reportability associated with 12.5.1lA.2 to determine environmental samples    applicability to the environmental groundwater sampling that is occurring as part of their investigation.
01 gI, No clear          CA-32                                                      NCS      6/20/06 delineation of            Update Exelon Management Model to define                  A8015ENV responsibilities between  responsibilities for low level radioactive spills.
corporate Environmental and Chemistry for low level radioactive spills.
41
 
Communications Plan:
Lessons Learned to        Communication Plan Action                                  Owner    Due Date be Communicated Elevated tritium levels in NER 1                                                      A8932CHEM Complete onsite monitoring wells;  Submit Preliminary NER (NER 1) for this event Elevated tritium levels in  NNOE 1                                                    A8932CHEM Complete onsite monitoring wells;    Submit preliminary NNOE (NNOE 1) for this event.
Blowdown line,              CA 33                                                      A8932CHEM 03/14/06 Secondary System            Create a station alignment slide that discusses the root Condensate and other        cause and actions for station personnel when they low level tritium system    discover liquid spills/leaks or liquid in areas where-leaks impact to State and  there should not be liquid.
Federal regulations for ground/drinking water.
Elevated tritium levels in  NER update (NER 2) per ATI 428868-12                      A8932CHEM 03/03/06 onsite monitoring wells;    Submit supplemental NER (NER 2) for this event Spills of liquids with low  which include a requirement for all Exelon sites to; level radioactivity may    1) Review all historical radiological spills/leaks to site impact State and Federal    property outside of the RCA.
regulations.                2) Verify tritium concentrations have been determined for the radiological spills/leaks or perform sampling to determine tritium concentrations for each of the radiological spills/leaks.
: 3) Determine impact of spilled tritium on environment.
: 4) Create additional actions as warranted to insure compliance with all Federal and State regulations and laws.
Elevated tritium levels in  Promulgate NER 2 to Exelon Nuclear Fleet to include:      A8076CHEM 03/13/06 onsite monitoring wells;    Submit supplemental NER for this event which include Spills of liquids with low  a requirement for all Exelon sites to; level radioactivity may    1) Review all historical radiological spills/leaks to site impact State and Federal    property outside of the RCA.
regulations                2) Verify tritium concentrations have been determined for the radiological spills/leaks or perform sampling to determine tritium concentrations for each of the radiological spills/leaks.
: 3) Determine impact of spilled tritium on environment Elevated tritium levels in  NNOE update (NNOE 2) per ATI 428868-13. Submit            A8932CHEM 03/10/06 onsite monitoring wells;    supplemental NNOE (NNOE 2) for this event Spills of liquids with low level radioactivity may impact State and Federal
-regulations.
42
 
Root Cause Report ATTACHMENTS
#                    Title                                  Notes 1 Charter                                  Revision 1 for improved scope clarity.
2 Barrier Analysis 3 Cause & Effect Analysis 4 E&CF Chart 5 Change Analysis 6 Circ water blowdown system background information 7 Tritium plume map 8 Review of Exelon Hazmat spill response procedures 9 Reportability Manual - LS-AA-1020 and LS-AA-1110 10 Summary of Applicable State, Federal, and Offsite Dose Calculation Manual (ODCM)
Regulations and Requirements for Tritium Releases to the Environment 11 Root Cause Report Quality Checklist 12 VB-2 and VB-3 detailed timelines 43
 
Attachment 1 Page 1 of 3 LS-AA-1 25-1001 Revision Root Cause Investigation Charter (rev 1)
Tritium Release from Braidwood Station with a Potential to Affect the Public Condition Report #:          428868 Sponsoring Manager:          Janice Kuczynski, Chemistry Manager Team Investigator(s):
Names                  Position                                Commitment
.,Jason Eggart          Braidwood Chemistry Lead Investigator    Full Time
'Tom Leffler            Root Cause Qualified Investigator        Full Time Randy Kalb            Dresden Chemistry Investigator          Part Time IKim Aleshire            Braidwood EP (ODCM) Investigator        Full Time Glen Vickers          LaSalle RP Investigator                  Full Time Scott Kirkland        Quad Cities Investigator                Part Time Jim Crawford          Braidwood Maintenance Investigator      Full Time John Gumnick          Corporate RP (CHP) Investigator          Part-Time Mike Miller            Braidwood Operations                    Part Time Jeff Burkett          Braidwood Operations                    Part Time
)Dan Stroh              Braidwood Engineering                    Full-Time
,Scott Sklenar          Hydrologist                              Part-Time Scope:
The scope of the root cause investigation is twofold:
The first focus of this root cause team is to determine the root cause(s) of the Tritium releases from Braidwood Station, which, although low level, had a potential to affect the public. This causal determination should include the large volume leaks, which occurred in 1998 and in 2000, as well as the smaller volume leaks, which both followed and preceded the 1998 and 2000 leaks. The responsibility for identifying and operationalizing corrective actions to prevent future unacceptable tritium releases to the environment is being addressed by the Braidwood Tritium Remediation Team under AR 435383.
44
 
Attachment 1 Page 2 of 3 This root cause team remains responsible for identifying corrective actions to address organizational weaknesses contributing to or causing the releases described above.
The second focus of this root cause team is to evaluate the effectiveness of Braidwood's response to the circulating water Blowdown leaks, which deposited tritiated water on the ground during 1998 and 2000 as well as during the smaller volume leaks, which both followed and preceded the 1998 and 2000 leaks. If this evaluation determines that Braidwood's response actions were not effective, this root cause team will determine the root cause and appropriate corrective actions for those ineffective response actions. The investigation will review response procedures, regulations, environmental impacts, and managerial effectiveness. As part of this second focus item, the team will review the response to known spills in 1998, 2000 and similar IRs. A review of year 2000 Root Cause corrective action effectiveness will be performed. Specifically, the team will look for any evidence that the actions to prevent recurrence were not effective. An E&CF Chart will be utilized for Change Analysis and Barrier Analysis. Tap Root Analyses will also be utilized.
To accomplish a timely report delivery, support will be required as noted above in Engineering, Hydrology, Maintenance, Operations, Offsite Dose Assessment, and Technical Writing.
The responsibility for remediating the existing condition of detectable tritium in groundwater on and in the vicinity of Braidwood Station is not the responsibility of this root cause team. Remediation of the existing condition of detectable tritium in groundwater on and in the vicinity of Braidwood Station is being addressed by the Braidwood Tritium Remediation Team under AR 435383.
Interim Corrective Actions:
As described above, an Issues Management Team (the Braidwood Tritium Remediation Team) has been formed to manage the recovery.
Additional Sampling is being performed and analyzed to fully define the affected areas.
The discharge piping is being reviewed for integrity.
Remediation plans will be developed and implementation initiated.
The Braidwood Tritium Remediation Team will maintain communications with Exelon, Regulatory personnel, the public, and INPO.
45
 
Attachment 1 Page 3 of 3 Root Cause Report Milestones:
: 1. Event Date                                      (11/30/05)
: 2. Screening Date                                  (12/07/05)
: 3. Completion of Charter (2 Days from MRC) [-03]  (12/09/05) 3a. Completion of Charter revision                  (02/08/06)
: 4. Status Briefing for Charter [-14]              (12/14/05)
: 5. Two Week Update & Draft RCR for Reviews [-07]  (12/21/05)
: 6. MRC Update & Draft RCR for Reviews [-08]        (12/28/05)
: 7. CAPCo Reviews of RCR [-15]                      (12/29/05)
: 8. Collegial Reviews of RCR [-15]                  (12/29/05)
: 9. MRC Update & Draft RCR for Reviews [-09]        (01/04/06)
: 10. Sponsoring Manager Report Approval [-14]        (01/04/06)
: 11. Root Cause delivered to PORC                    (01/24/06)
: 12. Review by PORC [-05]                            (01/26/06)
: 13. Revised Root Cause Report delivered to PORC    (02/20/06)
: 14. Revised Root Cause Report Reviewed by PORC      (02/22/06)
: 15. Final Root Cause Investigation Due Date [-04]  (02/23/06)
Prepared By:, Tom Leffleri Root Cause Qualified    02/06/06 1,vestigatov (Name)                              (Date)
Approved        Carl B. Dunn, Training Director    02/08/06 By:
For (Sponsoring Manager)            (Date) 46
 
Attachment 2 Page 1 of 11 Barrier Analysis Failed or ineffective barrier          How Barrier Failed    Why Barrier Failed                    Corrective action to Restore Barrier to Effectiveness Procedures            CF 3_
BwAP 750-4            - Hazmat was not    Lack of knowledge of    - Develop and implement Standard Exelon procedures to provide integrated and entered              Title 35 IAC part 620    detailed spill and leak response requirements to ensure full compliance with state Failed Barrier 1                            groundwater quality      and federal laws and regulations and integrate Exelon resources to respond to (FB-1)                                                              radiological leaks and spills. (CAPR 4)
                      - Procedure does not                          - See Training Failed Barrier actions prompt radiological response BwAPll00-16            - Hazmat was not    Lack of knowledge of    -Develop and implement Standard Exelon procedures to provide integrated and (FB-2)                entered              Title 35 IAC part 620    detailed spill and leak response requirements to ensure full compliance with state groundwater quality      and federal laws and regulations and integrate Exelon resources to respond to radiological leaks and spills. (CAPR 4)
Procedure does not                          -See Training Failed Barrier-actions prompt radiological response NSP-RP-6101            50.75(g) does not    Lack of knowledge of    - Develop and implement Standard Exelon procedures to provide integrated and (FB-3)                clearly address      Title 35 IAC part 620    detailed spill and leak response requirements to ensure full compliance with state tritium              groundwater quality      and federal laws and regulations and integrate Exelon resources to respond to radiological leaks and spills. (CAPR 4)
                                                                    -RP manager to present to peer group changes to 50.75(g) procedure to clearly address actions necessary for tritiated water spills, including evaluation for dose assessment to the public and initiate follow-up actions as appropriate to track necessary procedure changes. (CA-21)
                                                                    -Review 50.75(g) files to ensure tritium and or any other isotopes are included for all blowdown vacuum breaker water events and perform 50.75(g) evaluation for all blowdown vacuum breakers not previously completed. (CA-30)
                                                                    -See Training Failed Barrier actions 47
 
Attachment 2 Page 2 of 11 Barrier Analysis Failed or ineffective barrier        How Barrier Failed    Why Barrier Failed                Corrective action to Restore Barrier to Effectiveness RP-AA                  No guidance for low Lack of knowledge of      Develop and implement Standard Exelon procedures to provide integrated (FB-4)                level spills        Title 35 IAC part 620    and detailed spill and leak response requirements to ensure full compliance groundwater quality      with state and federal laws and regulations and integrate Exelon resources to respond to radiological leaks and spills. (CAPR-4)
                                                                      - See Training Failed Barrier actions WC-AA-106              WC called issues    Lack of knowledge of      - See Training Failed Barrier actions Attachment I implies a "C", not recognizing Title 35 IAC part 620    - Corporate Work Control to implement revision of WC-AA-106 to "B2" if increased      that sampling for    groundwater quality      incorporate a higher work priority for response to low level radioactive water sampling              tritium would be                              being released to the environment. (CA-26)
(FB-5)                required BwOA                  No guidance for low Lack of knowledge of      Develop and implement Standard Exelon procedures to provide integrated (Radiological spill    level spills        Title 35 IAC part 620    and detailed spill and leak response requirements to ensure full compliance procedure does not                          groundwater quality      with state and federal laws and regulations and integrate Exelon resources to exist)                                                                respond to radiological leaks and spills. (CAPR-4)
(FB-6)                                                                - See Training Failed Barrier actions LS-AA-1020 & 1110      Does not reflect    Lack of knowledge of      -Corporate Regulatory Assurance to perform an extent of condition review Reportability Manual  ODCM REMP/RETS Title 35 IAC part 620          regarding ODCM, REMP, RETS and state regulations for needed changes to (FB-7)                reporting            groundwater quality      the Reportability Manual and create additional actions as required. (CA-1l) requirements                                  -Corporate Regulatory Assurance to revise the Reportability Manual for reporting requirements of 35 IAC 611/620 Groundwater Tritium Release Path, 20,000 pCi/L limitations, and Illinois SB241 Community Right to Know requirements. (CA-12)
                                                                      - See Training Failed Barrier actions 48
 
Attachment 2 Page 3 of 11 Barrier Analysis Failed or ineffective barrier        How Barrier Failed      Why Barrier Failed                Corrective action to Restore Barrier to Effectiveness LS-AA-1020 & 1110 Does not reflect 35      Lack of knowledge of      -Corporate Regulatory Assurance, to perform an extent of condition review Reportability Manual IAC 620                Title 35 IAC part 620    regarding ODCM, REMP, RETS and state regulations for needed changes to (FB-8)                Groundwater Tritium groundwater quality        the Reportability Manual and create additional actions as required. (CA- 11)
Release Path, 20,000                          -Corporate Regulatory Assurance to revise the Reportability Manual for pCi/L limitations                              reporting requirements of 35 IAC 611/620 Groundwater Tritium Release Path, 20,000 pCi/L limitations, and Illinois SB241 Community Right to Know requirements. (CA-12)
                                                                      - See Training Failed Barrier actions LS-AA-1020 & 1110. ENV 3.26 does not        Lack of knowledge of      -Corporate Regulatory Assurance to perform an extent of condition review Reportability Manual clearly warn of        Title 35 IAC part 620    regarding ODCM, REMP, RETS and state regulations for needed changes to (FB-9)                tritium groundwater  groundwater quality      the Reportability Manual and create additional actions as required. (CA-1 1) quality standards                              -Corporate Regulatory Assurance to revise the Reportability Manual for reporting requirements of 35 IAC 611/620 Groundwater Tritium Release Path, 20,000 pCi/L limitations, and Illinois SB241 Community Right to Know requirements. (CA-12)
                                                                      - See Training Failed Barrier actions LS-AA-1020 & 1110      RAD 1.21, 10OCi      Lack of knowledge of      - See Training Failed Barrier actions Reportability Manual  tritium 24h release  tritium amounts released (FB-10)                limitation not checked LS-AA-1020 & 1110      SAF 1.9 New Right    No program for review    Review the process by which the company becomes aware of new Reportability Manual  to Know legislation  and promulgation of new  environmental laws and regulations for radiological and non-radiological (FB-11)                not reflected,      laws.                    issues and how they are integrated and communicated into company policies, programs, and procedures. Assign additional actions as necessary, if process changes are needed. (CA- 14) 49
 
Attachment 2 Page 4 of 11 Barrier Analysis Failed or ineffective barrier              How Barrier Failed    Why Barrier Failed        Corrective action to Restore Barrier to Effectiveness ER-BR-400-101        No precaution for    Lack of knowledge of      -Develop and implement Standard Exelon procedures to provide integrated Engineering          tritium groundwater  Title 35 IAC part 620    and detailed spill and leak response requirements to ensure full compliance Walkdown PM          concern              groundwater quality      with state and federal laws and regulations and integrate Exelon resources to Procedure                                                            respond to radiological leaks and spills.
(FB-12)                                                              (CAPR-4)
                                                                      - See Training Failed Barrier actions OBwOS CW-A1 OPS No precaution for          Lack of knowledge of      Develop and implement Standard Exelon procedures to provide integrated Walkdown PM          tritium groundwater  Title 35 IAC part 620    and detailed spill and leak response requirements to ensure full compliance Procedure            concern              groundwater quality      with state and federal laws and regulations and integrate Exelon resources to (FB-13)                                                              respond to radiological leaks and spills. (CAPR-4)
                                                                      - See Training Failed Barrier actions EN-AA-Environmental No guidance for        Lack of knowledge of      -Develop and implement Standard Exelon procedures to provide integrated procedures            radiological spills  Title 35 IAC part 620    and detailed spill. and leak response requirements to ensure full compliance (FB-14)              that can get to      groundwater quality      with state and federal laws and regulations and integrate Exelon resources to drinking water                                  respond to radiological leaks and spills. (CAPR-4) supplies                                        -See training failed actions barrier actions BwOP CW-12            No shutdown          Lack of knowledge of      - Ops to add precautions to BwOP CW-12, BwOP WX-526TI, & BwOP WX-(FB-15)              precautions during a  Title 35 IAC part 620    501TI for release shutdown on leak to environment and for the release release for a leak in groundwater quality      restrictions dealing with Reportability Manual Section RAD 1.21 (i.e.: 100 the blowdown system                            Ci. limit on tritium releases over a 24 hour period). (CA-20)
                                                                      -See training failed barrier actions BwOP WX-526TI,        No shutdown          Lack of knowledge of      - Ops to add precautions to BwOP CW-12, BwOP WX-526TI, & BwOP WX-(FB-16)              precautions during a Title 35 IAC part 620      501TI for release shutdown on leak to environment and for the release release for a leak in groundwater quality      restrictions dealing with Reportability Manual Section RAD 1.21 (i.e.: 100 the blowdown system                            Ci. limit on tritium releases over a 24 hour period). (CA-20)
                                                                      -See training failed  barrier 50
 
Attachment 2 Page 5 of 11 Barrier Analysis Failed or ineffective barrier              How Barrier Failed Why Barrier Failed                                      Corrective action to Restore Barrier to Effectiveness BwOP WX-501TI        No shutdown          Lack of knowledge of Title 35 IAC part 620          - Ops to add precautions to BwOP CW- 12, BwOP WX-526TI, (FB-17)              precautions during a groundwater quality                                  & BwOP WX-501TI for release shutdown on leak to release for a leak in                                                      environment and for the release restrictions dealing with the blowdown system                                                        Reportability Manual Section RAD 1.21 (i.e.: 100 Ci. limit on tritium releases over a 24 hour period). (CA-20)
                                                                                                - See training failed barrier actions Alarms/              Other Issue Annunciators "a" Leak detection on    Only performed        Not often enough to detect leaks. System has        Braidwood System Engineering to review operation of the CW vacuum breakers      annually at the time  inherent suspended materials in the CW, which        lowdown system and determine the optimum monitoring scope (FB-18)              of the 1998 event,    can cause the valves to stick open, allowing        nd frequency of inspection PM's and walk downs for the Recently performed    tritiated water to be released.                      ,ystem. If applicable, identify gaps and create additional ATI's on semi-annual basis.                                                      s required (CA-22)
Currently (Since Sept. 2005)                                                                -Braidwood System Engineering to research and evaluate performed monthly                                                          passive vacuum breaker replacement options and present findings to PHC for approval if the CW Blowdown system will be used for radiological releases in the future (CA-23)
Alarms and            Did not alarm        Did not exist. Neither the Operations Department,        System Engineering to work with Design Engineering to annunciators                                which is responsible for operating and monitoring        research and evaluate viable remote monitoring (FB-19)                                    the CW B/D System, nor Plant Engineering, which          instrumentation systems that can detect lower level external has responsibility for managing the CW B/D              leakage from the blowdown system and automatically notify System, recognized the need for, nor did they            Braidwood Operations if the CW blowdown system will be pursue installation of a remote detection system        used for radiological releases. (CA-24) for each vacuum breaker. Such a system may have allowed earlier detection and isolation of the leaks described in Table 1, which could have reduced environmental impact.
51
 
Attachment 2 Page 6of 11 Barrier Analysis
'Failed or ineffective barrier        How Barrier Failed        Why Barrier Failed                Corrective action to Restore Barrier to Effectiveness Preventative          CF-1 maintenance/
design configuration Piping/Valves          Water hammer events Changed BwOP-CW12              BwOP CW-12 revised to mitigate water-hammer - revision 14.
equipment failures                            and created a water        (Completed, 01/19/01) . Corrective actions reversed by a subsequent (FB-20)                                      hammer issue                revision.
Corrective actions to be addressed under IR 453381. (CA-31)
Inadequate              R Lack of preventative      Institute a Preventative Maintenance Program and system modifications, preventative                maintenance program    which are complete and have been verified to be effective in preventing maintenance                for these valves        major valve failures that result in large volume spills. (CAPR 1) programs and            v Valves were not inadequate design          designed to handle configuration              the water hammer events Training              CF-7 Certification of      No training on a      Did not know Title 35      Generate TR to analyze the chemistry management and technician level of Chemistry personnel    response to a liquid  IAC part 620 groundwater    knowledge regarding the CW B/D system and the radioactivity expected to (FB-21)                radiological spill for Tritium concentration      be present. Refer to the Root Cause Report to be used as a case siudy.
requirements of Title  limits                      (CA-18) 35 IAC part 620 groundwater quality.
52
 
Attachment 2 Page 7 of 11 Barrier Analysis Failed or ineffective barrier        How Barrier Failed        Why Barrier Failed                Corrective action to Restore Barrier to Effectiveness Licensed and Non-        No Environmental      Did not know Title 35    Generate TR to analyze the operations personnel level of knowledge licensed Operator        spill training for low IAC part 620 groundwater regarding the CW B/D system and the radioactivity expected to be present.
initial and              level radioactive      quality                  Refer to the Root Cause Report to be used as a case study. (CA-19) requalification training liquids (FB-22)
Certification of RP/HP  Lack of cert guide for Did not know Title 35    Generate TR to analyze the RP management and technician level of (FB-23)                  low level radioactive IAC part 620 groundwater knowledge regarding the CW B/D system and the radioactivity expected to be liquid spills          quality.    -              resent. Refer to the Root Cause Report to be used as a case study. (CA-17)
Regulations              CF-5 ODCM requires            Braidwood has          Did not know Title 35        Evaluate the groundwater and food crop pathway per ODCM Table 12.5-1 evaluation of            demonstrated a        IAC part 620 groundwater    Section 3.a note (6). Assign additional actions as necessary, if the pathway groundwater pathway if credible pathway        tritium concentration        is credible. (CA-15) credible                                        limits (FB-24)
ODCM requires            Braidwood has          Did not know Title 35    Revise the Site specific portions of the ODCM to incorporate the new evaluation of            demonstrated a        LAC part 620 groundwater  monitoring wells as determined by the ODCM Environmental Specialist to be groundwater pathway if credible pathway        Tritium concentration    credible groundwater (well water) monitoring sources into the ODCM Table credible                                        limits                    11-1 Section 3.a note (6) and ODCM REMP Table 12.5-1 Section 3a Note (FB-25)                                                                  (6).groundwater. (CA-16)
Title 35 IAC part 611 ODCM does not            Did not know Title 35    Review the process by which the company becomes aware of new groundwater quality      reflect state          IAC part 611 groundwater environmental laws and regulations for radiological and non-radiological (FB-26)                  groundwater            quality                  issues and how they are integrated and communicated into company policies, requirements                                    programs, and procedures. Assign additional actions as necessary, if process changes are needed. (CA-14) 53
 
Attachment 2 Page 8 of 11 Barrier Analysis Failed or ineffective barrier              jHow Barrier Failed jWhy Barrier Failed        Corrective action to Restore Barrier to Effectiveness Title 35 IAC part 620  ODCM does not      Did not know Title 35    Revise the Midwest ODCM and/or program procedures to incorporate the groundwater quality    reflect state      IAC part 620 groundwater  State of IL requirement of <20,000 pCi/L of tritium for groundwater (35 IAC (FB-27)                groundwater        quality standards.        620.410.e).3)) and the State of IL requirement for non-degradation (35 IAC requirements.                                620.301.a)) (CA-5)
Revise the ODCM and/or program procedures as warranted to incorporate the State of PA requirements for radioactivity in groundwater. (CA-6)
Revise the ODCM and/or program procedures as warranted to incorporate the State of NJ requirements for radioactivity in groundwater (CA-7)
Clearly define to each station (extent of condition), the changes to the ODCM based on review of Illinois laws governing radioactive contamination of groundwater (potable water). Assign additional corrective actions to ensure site's ODCM reflects and implements applicable regulations. (CA-8)
Clearly define to each station (extent of condition), the changes to the ODCM based on review of Pennsylvania laws governing radioactive contamination of groundwater (potable water). Assign additional corrective actions to ensure site's ODCM reflects and implements applicable regulations. (CA-9)
Clearly define to each station (extent of condition), the changes to the ODCM based on review of New Jersey laws governing radioactive contamination of groundwater (potable water). Assign additional corrective actions to ensure site's ODCM reflects and implements applicable regulations. (CA-10)
Review the process by which the company becomes aware of new environmental laws and regulations for radiological and non-radiological issues and how they are integrated and communicated into company policies, programs, and procedures. Assign additional actions as necessary, if process changes are needed. (CA-14) 54
 
Attachment 2 Page 9 of 11 Barrier Analysis Failed or ineffective barrier              .. How Barrier Failed    Why Barrier Failed          Corrective action to Restore Barrier to Effectiveness Corporate Oversight    Did not uncover 2    Corporate audits did not    Revise CY-AA- 170-000 and associated procedures to require audits of the CY-AA-170-000,          missing State        check program to            ODCM against applicable laws and regulations at an acceptable frequency.
CY-AA-170-100,          regulations or the    sufficient detail          Review the need for revision to include State regulations into Step 4.2.1 basis CY-AA-170-1000,        state groundwater                                of the ODCM. Create additional actions as warranted. (CA- 13) tritium concentration CY-AA-170-200,          issue.
CY-AA- 170-2000, CY-AA-170-2000, CY-AA-170-300, CY-AA-170-3100.
(FB-28)
Notification            CF-6 NOS Audit NOSA-        Did not uncover two  NOS Audit Plan did not      Discuss this RCR with the Corporate NOS Peer Group to evaluate changing BRW-05-08 (AR          (2) missing state    check program to            the NOS auditing template standard for the ODCM Program. Document 2877 18) November 22, regulations or the      sufficient detail, did not  results and assign additional actions as required. (ACIT-28) 2005                    state groundwater    verify ODCM met (11-29)                tritium concentration applicable state issue                regulations Notice to other Site    Did not always        No procedure to assure      Develop and implement Standard Exelon procedures to provide integrated Departments when an    inform all affected  consistent approach to      and detailed spill and leak response requirements to ensure full compliance event occurred          parties              leaks/spills                with state and federal laws and regulations and integrate Exelon resources to (FB-30)                                                                  respond to radiological leaks and spills. (CAPR-4) 55
 
Attachment 2 Page 10 of 11 Barrier Analysis Failed or ineffective barrier                How Barrier Failed Why Barrier Failed          Corrective action to Restore Barrier to Effectiveness Notice to sites of new Sites not informed of Program not robust      Review the process by which the company becomes aware of new State Regulations      new Illinois SB241,                            environmental laws and regulations for radiological and non-radiological (FB-31)                Community Right to                              issues and how they are integrated and communicated into company policies, Know                                            programs, and procedures. Assign additional actions as necessary, if process changes are needed. (CA- 14)
Work Orders            Other Issue Model PM work orders  Failed to have RP      Did not know Title 35    - RP to provide information to Work Planning so that a work standard can be and current work      sampling of leaks and IAC part 620 groundwater  created for work activities that involve potentially tritiated water. This orders for B/D vacuum  how to properly        quality                  information will be used to update PM model work orders and current work breakers              dispose of liquids not                          orders involving potentially triiiated water. (CA-25)
(FB-32)                in work order                                  - Using the information provided by RP, create a work standard to be used for instructions.                                  work activities that involve potentially tritiated water and update PM model work orders and current work orders involving potentially tritiated water (RWP, sample for tritium, instructions for pumping tritiated water). (CA-27) 56
 
Attachment 2 Page 11 of 11 Barrier Analysis Failed or ineffective barrier                How Barrier Failed Why Barrier Failed          Corrective action to Restore Barrier to Effectiveness Oversight              CF-4 and CF-2 Weak management        CF4: Braidwood        Lack of questioning      OP-AA-106-101-1002, Exelon Nuclear Issues Management, will be revised review and oversight of Senior Management attitude regarding            to: 1) improve Corrective Action Program (CAP) controls of Issues spill response          did not question the unplanned spills from the Management teams, 2) utilize the tools and techniques of the Exelon HU-AA-activities.            radiological impact of blowdown system.          102 and HU-AA-1212, Technical Human Performance Practices and (FB-33)                all leaks that had                              Technical Task Risk/Rigor Assessment, Pre-Job Brief, Independent Third happened.                                      Party Review, and Post-Job Brief procedures, 3) strengthen reporting requirements to affected station Senior Management, and 4) define affected station Senior Management responsibilities for "cradle to grave" oversight and challenge of events and issues. (CAPR 5)
CF2: Lack of          Did not know Title 35    The Braidwood Tritium Remediation Team will determine the methodology questioning attitude  IAC part 620 groundwater and implement the plan for future radiological releases, including leakage for low level          Tritium concentration    standards. (CAPR 2) radiological spills. limits                  Develop a case study of this event. Provide initial and continuing training for The need for a near                            MRC/SOC members. (CA-2) zero leakage standard was not identified.                            Evaluate conducting Dynamic Learning Activity (DLA) on a Duty Team basis using 2000 release conditions and revised response and reporting procedures implemented in CAPR 4. Create additional assignments as warranted. (CA-3)
Review other potential leaks beyond tritium to address extent of condition regarding Exelon management's control of hazardous material spills. If deficiencies are noted, write IR's to have those deficiencies addressed.
(CA-4) 57
 
Attachment 3A
                              -Cause & Effect Analysis Effect Symptom                  Why                              Cause / Reason Vacuum breaker leaks                                    Small 'leaks were never considered to occurred after 2000                                    be a problem Small leaks were never                                  2000 Root Cause Team only considered .to be a problem                            addressed major failures 2000    Root Cause Team 2000only adr  sed TemajThe                                  2000 charter was to determine the only addressed major                                    major failures failures
* The charter was narrowly scoped due The 2000 charter was to                                to two teams were developed to determine the major failures                            perform the Root Cause and Radiological spill Response The charter was narrowly scoped due to two teams                                Was not considered a problem as were developed to perform                              small leaks did not leave the site the Root Cause and Radiological spill Response 58
 
Was not considered a problem as small leaks did                People did not know the 1991 statute not leave the site                        for groundwater.
The need for a near zero leakage 1991lestatte for                          standard was not identified, due to a gr    d watutefor.                        lack of Technical Rigor/Questioning groundwater.                &#xf7;Attitude              (Root Cause 2).
The need for a near zero leakage standard was not identified, due to a lack of              At this time the HU-AA-1212 and 102 Technical Rigor/                          procedures did not exist.(CAPR 3)
Questioning Attitude (Root Cause 2).
59
 
Attachment 3B
                              -Cause & Effect Analysis Effect I Symptom              Why                    Cause / Reason Tritium found off site                                        Inadequate response Personnel not aware of the B/D water Tritium exceeding groundwater Inadequate response                                limits. Belief that release package authorized unrestricted release to environment.
Personnel not aware of the B/D water Tritium                                  Personnel not aware of the IEPA exceeding limits. Belief that                              tritium limit requirements for release package authorized                                          groundwater unrestricted release to environment.
Personnel not aware of the JEPA tritium limit                                        Knowledge deficiency requirements for groundwater No integrated procedural guidance for Knowledge deficiency                              groundwater radiological spills (Root Cause 3) 60
 
Attachment 3C
                                  -Cause & Effect Analysis Effect I Symptom                  Why                    Cause / Reason Tritium found off site                                      Ineffective response in 2000 Ineffective response in                                  Sampling not performed for tritium in 2000                                                        groundwater Sampling not performed for                                  Poor decision by Spill Team not to tritium in groundwater                                                  sample Poor decision by Spill                                      Weak questioning attitude and Team not to sample                                        inadequate challenge culture (Root Cause 4)
OP-AA-106-101-1002 (currently, OP-Weak questioning attitude                                    AA-101-503 in year 2000) was not and inadequate challenge                                    specific enough in regarding culture                                          management reporting requirements
_(CAPR                                                5) 61 E&CF Chart
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o r~aeledT,-r)st EF33 kwt, mlak (
c on.t.j fks&*U 64
 
Attachment 5 Change Analysis (The Change Analysis tool was inadequate to use effectively and was therefore not utilized as an input to this root cause report.)
Factors That        Interview        Successful      Failed          Change?  Causal Influence          Questions        Performance    Performance              Factor?
Performance Factors That Influence    Interview      Successful    Failed        Change?  Causal Performance                Questions      Performance    Performance            Factor?
Factors That      Interview        Successful      Failed            Change?  Causal Influence        Questions        Performance      Performance                Factor?
Performance 65
 
Attachment 6 Page 1 of 6 Circ Water Blowdown System BACKGROUND INFORMATION The primary function of the Circulating Water Blowdown System is to provide for lake turnover to prevent undesirable chemical buildup in the lake. The secondary function of the Circ Water Blowdown System is to provide dilution for liquid rad waste releases. (See Attachment 7 for map.)
The Circulating Water Blowdown System is designed to return Cooling Lake water back to the Kankakee River. Processed fluids from the Sewage Treatment System and the Radwaste Treatment Systems discharge directly into the Circulating Water Blowdown system, where dilution occurs prior to release to the Kankakee River. The Wastewater Treatment Plant and the De'mineralizer Regenerant Waste systems along with various strainer/filter backwashes are returned to the Cooling Lake and thus are indirectly returned to the Kankakee River through the Blowdown line after dilution by the Cooling Lake.
The Circ Water Blowdown system begins at the Circ Water System supply piping to the condenser. Two 24" carbon steel pipes tap off the Circulating Water supply piping (one from each unit) and combine into-a 36" common header. A motor operated isolation valve (1/2CW018) is provided on each 24" line. The 6" Radwaste Treatment System discharge pipe connects to the 36" blowdown header. Downstream of the radwaste connection, the blowdown pipe is expanded to 48" prior to connection to the 3" Sewage Treatment Plant discharge pipe.
The 48" diameter blowdown pipe is reinforced concrete pipe (RCP) and runs along owner-controlled property until reaching the Blowdown structure at the Kankakee River. Eleven vacuum breaker assemblies are incorporated at the high points along the 48" diameter RCP to prevent pipe implosion when the blowdown system is shut off. The 48" RCP is split and reduced to two 24" discharge pipes at the Kankakee River blowdown structure. Each 24" discharge pipe was originally equipped with a motor operated spray valve. The entire piping network is approximately 29,000 ft long and was originally operated at about 12,000 gpm (-2.5 ft/s).
The Circ Water Blowdown system was originally designed to be maintained full of water and pressurized. This was accomplished through manipulation of the Blowdown Spray Valves, at the Kankakee River blowdown structure. These valves were susceptible to freezing due to their location and system operation requirements. Based on this, other maintenance issues, and parts obsolescence, these valves were eventually abandoned in the full open position in the late 66
 
Attachment 6 Page 2 of 6 1980's-. To allow-air release from the piping on start-up and to allow air introduction to protect against vacuum damage to the piping, vacuum breakers are installed.
                          'VA    EMA9
* 0j"      N    i.9          I NOTE: Above is typical. Braidwood has 48" reinforced concrete pipe. Other differences may apply.
System control was transferred to the upstream motor operator isolation valves located in the turbine building. This modification caused the blowdown line to operate in a partially voided condition in various locations, depending on elevation which allowed column separation water hammer events to occur when flow rates were changed significantly, i.e.; during system start-up or shut down.
Events were not initially seen because blowdown was essentially in service all the time. As a result of this change in operational methodology, the blowdown system would no longer be maintained full and pressurized upon shutdown.
Minimal technical review was performed on the hydraulic transient effects on the vacuum breakers from this method of operation.
67
 
Attachment 6 Page 3 of 6 A more rigorous technical review may have initiated the installation of surge protected check valves (which eventually occurred in 2001) before the majority of the leaks described in this report occurred. This is a missed opportunity.
In 1997, the Chemical Feed System was relocated from the Turbine Building to the Lake Screen House under modification M20-0-95-003. One of the primary reasons for centralization of the Chemical Feed system to the Lake Screen House was to reduce maintenance cost. This design change necessitated isolating the Circ Water Blowdown System on a daily basis to accommodate biocide injections into the Circ Water System, because our permits do not authorize discharge of biocide to the Kankakee River. When both units were in operation this was not an issue because partial blowdown flow was maintained from the unit not being chlorinated. The problem became apparent during outages when one unit was shut down. In this configuration, blowdown flow was stopped and started whenever the operating unit was chlorinated.
The daily requirement to isolate Circulating Water Blowdown for biocide injection, prompted the Operations Department to challenge the BwOP CW-12 procedural requirement to slowly open the motor operated valves for system start-up.
BwOP CW-12 was revised to allow fast motorized operation of motor operated valves, in lieu of slower manual throttling following short periods of system shutdown (i.e.: biocide injections).
68
 
Attachment 6 Page 4 of 6 Typical vacuum breaker:
AI R. RE LEASE VALVIE Ah%11 B lITTERLY VALVE 10 IFVI0 h4AL-CSIEE  C"P34AW.V~ EWW)V:
                  ~*~Efl.ata I.S.O MI.SScMJCWSC.,r Work history on the Circulating Water Blowdown System vacuum breakers was reviewed. There were no recorded vacuum breaker float assembly failures prior to 2000, however several instances of leaking air release valves were noted from the review. The VB-3 air release valve was discovered leaking in 12/98. PIF #
A1998-04324 was generated to address the flooding of site property and the Smiley Road ditch immediately adjacent to site property. The piping to the air release valve on the VB-1 failed in 12/96. The complete vacuum breaker assembly including air release valve was replaced with a new assembly in 1997.
It should be noted that the VB-1 vacuum breaker failed again on 11/20/2000. The float assembly broke at the bowl to guide bar weld. No other significant work history was identified.
The failure of the VB-2 float assembly was discussed with the vendor. Based on the failure description, the vendor indicated that it appeared to be consistent with the effects of a pressure surge (i.e. water hammer). The vendor indicated that surge protection check valves should be considered for a vacuum breaker when pipe flows exceed 6 ft/s and are required when flow velocities exceed 10 ft/s.
The vendor also recommended a 7-10 year PM frequency to address valve elastomer degradation. The condition was addressed by revising the operating procedure BwOP CW-12 to manually open and close the valves to slowly initiate or terminate blowdown flow.
69
 
Attachment 6 Page 5 of 6 The present circulating water blowdown system operates as follows. On system startup, the air/vacuum valve exhausts large amounts of air from the piping system until the float assembly in the air/vacuum valve rises with water level to close and seal during normal system operation.. To prevent the inrushing water from causing damage to the air/vacuum valve float, a surge check valve is installed just underneath the air/vacuum valve. The surge check is a spring loaded, normally open valve, which passes air through unrestricted. When water rushes into the check valve, the disc begins to close against the spring tension and reduces the flow rate of water into the air/vacuum valve by means of throttling holes in the disc. This ensures gentle closing of the air/vacuum valve float, regardless of initial flow velocity into the valve and minimizes pressure surges. Upon system shutdown, the vacuum valve is designed to open as water level decreases. The air release valve provides two functions. The primary function is to release small amounts of entrained air that accumulates at the high points during normal system operation. If not removed, this air that would increase head loss and reduce process flow. The air release valve also facilitates earlier opening of the main air/vacuum valve on system shutdown. On shutdowns, air pockets that develop at high points may be at positive pressure, tending to hold the main air/vacuum float on its seat even though water level is below the float assembly. However, the air release valve will vent the air and allow the main air/vacuum valve to open as soon as water level drops. Each vacuum breaker is provided with a butterfly isolation valve to facilitate vacuum breaker maintenance.
Modification of 2001-2003 changed the design of the air / vacuum valve assembly to a slow closing design with the use of a surge protector valve in-line.
This modification protects the air/vacuum valves from pressure surges experienced during water hammer events.
Modification of 2003 installed CW Blowdown Booster Pumps to increase the blowdown flow rate to 25,000 gpm for improving lake chemistry. With increased flow rates during booster pump operation the volume of voided blowdown line may decrease, closing previously open air / vacuum valves under lower flow conditions. Start up and shut down procedures for the booster pumps specify flow / pump increase / decrease ramp rates to minimize potential column separation water hammer pressure surges.
70
 
Attachment 6 Page 6 of 6 Modification of 2005 installed a de-chlorination modification to allow continuous operation of the Blowdown System while performing unit chlorination. This modification allowed blowdown to be in-service essentially all the time, reducing the potential for air / vacuum valves leaks caused by system flow rate changes.
The aggregate impact of the three modifications was to assure nearly continuous operation of the blowdown system which minimizes the inclusion of air and the possibility of damaging water hammer at the vacuum breaker valves.
71
 
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-23D - TiriuhA Or-6TOUR                                                                          ESTIMATED TRITIUM RESULTS DEEP GROUNDWATER ZONE EXELON GENERATION BRAIDWOOD STATION JANUARY 30, 2006                                                                                              sracev/lle, linicis 73
 
NTnrth Godley  Braidwood Illinois  Station Kankakee River 75
 
Attachment 8 Review of Exelon Hazmat Spill Response Procedures Page 1 of 3 In general, there is no spill response procedure, which would acknowledge the subsurface water transport mechanism from onsite to offsite locations. The three documents reviewed were a draft procedure circulated in 10/16/90, "General Action Plan for Response to Unmonitored Releases and Very Low Level Radioactive Spills", BwAP 750-4, "Hazardous Material Spill Response", and BwAP 1100-16, "Fire/Hazardous Materials Spill and/or Injury Response", and NSP-RP-6101, "10 CFR 50.75(g)(1) Documentation Requirements".
The most significant barrier deficiencies noted was that the 1990 draft procedure may have prompted reviewing hydrology and dose to the public from radiological contamination of groundwater. Additionally, the procedure to document the spill for 10 CFR 50.75(g)(1) requirements for decommissioning prompts to perform a potential dose impact to the public from the spill, but does not require any specific pathway (i.e. subsurface migration of contaminants to drinking water).
Procedure                                  Relevant Content                              Barrier Analysis Draft Procedure CSG-001,      The draft procedure contained pertinent information about:          Missed opportunity to "General Action Plan for
* For situations involving subsurface contamination,          erect a barrier.
Response to Unmonitored                corrective action may mean the preparation of a Releases and Very Low Level            submittal pursuant to the I1Adm. Code 340.3020 and 10      This procedure may have Radioactive Spills"                    CFR 20.302 requesting the in-place disposal of              prompted recognition of subsurface contamination,                                  dose impacts from the Circulated as a Draft
* Environment - refers to any surface water, groundwater,        contamination of procedure 10/16/90. No                sanitary or storm sewers, soil, land surface, or subsurface groundwater and record of this becoming an            strata and vegetation,                                      supporting hydrology actual procedure.
* Subsurface contamination and hydrology 'concerns            issues.
0 Reviewing to ensure the spill is not in excess of This procedure contains              Reportable Quantity quantities in 40 CFR 302 App B or        May have provided an information relevant to the          40 CFR 355 App A                                            opportunity for all former underground water dose            0 Required evaluation of exposure pathways from                  CornEd nuclear plants to pathway to the public now            infiltration and contamination of groundwater.              recognize the potential being evaluated. Not                                                                              issue.
implementing this procedure was a missed opportunity to erect a barrier to recognize Page 2 of 3 BwAP 750-4, "Hazardous      In general, site personnel would not consider entry into the          Minor missed barrier.
Material Spill Response"    hazmat spill procedure for a water spill.
The procedure contains the following pertinent information:          Missing this barrier was
* The procedure references Hazardous Materials as listed in        of no consequence. The 40 CFR 302.4, which lists many chemicals, but not            RP organization did not 76
 
Procedure                                    Relevant Content                            Barrier Analysis radioactive material. The intent of this reference is to    have subsequent ensure that a "Reportable Quantity" has not been spilled    proceduresto respond to on the ground. The absence of radioactive materials        the subsurface transport from the list in the procedure does not preclude someone    issues, which are of issue from looking for radioactive material in 40 CFR 302.4,      today.
but the procedure does not offer a clear barrier to trip recognition of a radioactive material spill as a hazmat event per this procedure. Even if radioactive materials was clearly on the Reportable Quantity list, the RP organization does not have a procedure documenting additional required actions.
The procedure states, "Spills containing radiologically contaminated material shall be reported to the Radiation Protection Dept.
BwAP 1100-16,                The hazmat procedure does not contain information to specify          Minor missed barrier.
"Fire/Hazardous Materials    actions that might direct specific radiological actions to minimize Spill and/or Injury Response" the significance of a similar event. The procedure essentially        Missing this barrier was defers radiological spills to the RP organization. The procedure      of no consequence. The contains the following radiological information:                      RP organization did not Notify Rad Protection to dispatch personnel to the          have subsequent fire/spill area for radiation detection and first aid      procedures to respond to purposes.                                                  the subsurface transport issues, which are of issue today.
Page 3 of 3 NSP-RP-6 101, "10 CFR        This procedure is intended to provide the following information      Missed barrier 50.75(g)(1) Documentation    as required from the regulation:
Requirements"
* 10 CFR 50.75(g)(1) Records of spills or other unusual          The procedure requires an occurrences involving the spread of contamination in        assessment of potential and around the facility, equipment, or site. These records  dose to the public from may be limited to instances when significant                the remaining radioactive contamination remains after any cleanup procedures or      material, but does not when there is reasonable likelihood that contaminants      prompt for the pathway of may have spread to inaccessible areas as in the case of      subsurface migration possible seepage into porous materials such as concrete. through groundwater to These records must include any known information on        drinking water.
identification of involved nuclides, quantities, forms, and concentrations.
* The actual procedure requires addressing:
o Concentrations of involved radionuclides o Quantities of material(s) o Forms of material(s), (e.g. solubility and permeability of the contaminant) o Description of the event o Impact of the remaining radioactive material on the health and safety of the public o Affected areas
* The procedure prompts to perform a potential dose impact to members of the public, but it does not describe pathways to be analyzed (i.e. subsurface migration of contaminants to drinking water). The general absence of tools to calculate the specifics of subsurface transport mechanisms may have prompted actual measurements through the drilling of wells to sample water or sample existing offsite wells. Corrective Action (CA-2 1) addresses performing a dose assessment to determine the dose impact to the public from radiological spills by including this action in the 10 CFR 50.75(g)(1) procedure. The purpose of corrective action 21 is to link 77
 
Procedure            Relevant Content                      Barrier Analysis the 10CFR 50.75(g) with the ODCM for tracking the impact on dose of isotopics in groundwater.
78
 
Attachment 9 Reportability Manual Review - LS-AA-1 020 and LS-AA-1 110 Page 1 of 3 Various documents were reviewed by this Root Cause Investigation Team to determine the expected reporting requirements for an event such as discovering radiologically contaminated water leaking from a plant system onto the ground within the owner-controlled area.
LS-AA-1020 Radiological Decision Tree was reviewed. The Liquid Release or Spill portion of the tree references SAF 1.9, News Release or Notification of Other Government Agency. SAF 1.9 requires NRC notification for any event related to the health and safety of the public or onsite personnel, or protection of the environment requiring a news release or notification of another government agency. One example described is the unplanned release of radioactively contaminated materials. Since the vacuum breaker leaks (spills) were contained onsite, the leak would not be characterized as a release per the Offsite Dose Calculation Manual.
Since the leak was onsite, there was no perceived health or safety risk to the public. A review of several Incident Reports (IR's) indicates that these leaks were not considered a public risk since the leaks were onsite. These IR's also reasonably concluded that National Pollution Discharge Elimination System (NPDES) violations did not occur and therefore, Environmental Protection Agency (EPA) notification was not required. Based on the nature of the leak, there was no safety or health risk to onsite personnel. Therefore, it was reasonable to conclude that these events were not reportable per SAF 1.9.
The Liquid Release or Spill portion of the Radiological Decision Tree also references RAD 1.1, Events Involving Byproduct, Source or Special Nuclear Material that Cause or Threaten to Cause Significant Exposure or Release. One of the reporting requirements concerns the release of radioactive material inside or outside the restricted area, but is not reportable if the location is not normally stationed during routine operations. Since personnel would not normally be stationed at the vacuum breakers, reporting was not required.
RAD 1.4, Liquid Effluent Release requires reporting when radioactive material is present at levels greater than 10 times applicable limits. The piping leaks were within the restricted areas and therefore were not considered an effluent release. Migration of contaminated groundwater offsite should be considered an effluent release, but was not considered. To date, measurable tritium concentrations in groundwater offsite are within 10 times the applicable limits. The event is not reportable per RAD 1.4.
RAD 1.8, Effluent Release was not considered applicable since a release normally occurs at the authorized or intended discharge point. Therefore, reportability per RAD 1.8 was not considered. Offsite release via groundwater was not considered. Based on the measured tritium results off site, the requirements described in RAD .1.8 have not been exceeded and therefore, reportability per RAD 1.8 is not required.
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Attachment 9.
Reportability Manual Review - LS-AA-1 020 and LS-AA-1110 Page 2 of 3 RAD 1.21, Release of Radionuclides, requires reporting when the limits of 40 CFR 302 are-exceeded. For tritium, the 40 CFR 302 limit is 100 Curies released within a 24-hour period.
Review of effluent release data indicates that the 100-curie limit was not challenged during radioactive releases over the vacuum breaker leakage timeframe. Therefore, reportability per RAD 1.21 was not required.
RAD 1.22, Release of Hazardous Substances-(including radionuclides) is not applicable based on the RAD 1.21 discussion.
The other sections of the Liquid Release or Spill portion of the Radiological Decision Tree do not apply.
The other sections of the Radiological Decision Tree were reviewed and do not apply.
LS-AA-1020 Environmental decision tree was also reviewed. The Other Significant Event section was reviewed. ENV 3.26 Unusual or Important Environmental Events requires reporting of any event that did or could have significant environmental impact. It is reasonable that a blowdown water spill onsite would not have a significant environmental impact and therefore notification would not be made. However, potential groundwater contamination and migration to public wells was not considered.
The other sections of the Environmental Decision Tree were reviewed and would not apply.
40 CFR 141.16 states that the average annual tritium concentration shall not exceed 20,000 pCi/L in a community drinking water system. A community drinking water system is defined in the regulation as a public water system that serves at least 15 year round residents. The reportability manual appropriately references 40 CFR 141.
35 IAC 620 has the same 20,000 pCi/L limit and definition of community drinking water system as described in 40 CFR 141.16. However, 35 IAC 620 does not limit the tritium concentration to community drinking water. This Illinois standard limits tritium concentration in "Class I: Potable Resource Water," which is defined, in part, as water located 10 feet or more below the surface that is capable of potable use. Per discussion with Conestoga-Rovers & Associates and the Exelon Hydrologist, onsite groundwater at Braidwood station is classified as Class I: Potable Resource Water in accordance with 35 IAC 620. Therefore, any tritium leakage into the groundwater onsite could exceed the requirements of 35 IAC 620.
The reporting requirements for the Radiological Environmental Monitoring Program (REMP) are specified in the Braidwood ODCM, section 12.5.1. Table 12.5-2 lists REMP reporting levels for tritium and other radionuclides that are monitored in various types of samples obtained. These ODCM required reporting requirements are not listed in the Reportability Manual. Groundwater samples indicate that the reporting level of tritium per Table 12.5-2 have been exceeded.
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Attachment 9 Reportability Manual Review- LS-AA-1020 and LS-AA-1110 Page 3 of 3 The Braidwood ODCM REMP drinking water tritium concentration reporting requirements are consistent with the requirements of 40 CFR 141 and 35 IAC 620. However, per ODCM Section 12.5.1, reportability is based on a quarterly average. 40 CFR 141 and 35 IAC 620 reportability are based on an annual average - the ODCM reportability is conservative and consistent with the recommendations in NUREG 1301 Section 3.12.1.
There is no mention of 35 IAC 611 or 35 IAC 620 requirements in the Braidwood ODCM (CA4).
The Reportability Manual was reviewed for references to the various drinking water and groundwater standards. There is appropriate reference to 40 CFR 141 and 35 IAC 611.
However, there were not sufficient references to 35 IAC 620. Based on this review, there was inadequate knowledge of the requirements of 35 IAC 620 and the transport of radioactivity offsite via the groundwater pathway.
In 2005, Illinois passed SB241, which became effective on July 25, 2005. This legislation states that if the Illinois Environmental Protection Agency (IEPA) makes a determination that groundwater poses a threat of exposure above Class I groundwater standards (35 IAC 620),
then public notification is required. The IEPA does not require conclusive evidence of exceeding a standard. The notification can be based on modeling that demonstrates a trend towards exceeding a standard.
While this legislation does not require site reporting and does not change daily operation, it does impact the site because public notification can be made based on groundwater contaminant concentrations that are below reportable thresholds. There is no mechanism in place for site technical expertise to be made aware of new legislation such as Illinois SB241 (CA8).
References Braidwood Offsite Dose Calculation Manual LS-AA-1020, Reportability Reference Manual, Revision 8 LS-AA-1 110, Reportable Event SAF, Revision 6 LS-AA-1 120, Reportable Event Radiation (RAD), Revision 3 LS-MW-1 310, Reportable Event SAF, Revision 3 LS-MW-1 340, Reportable Event, ENV, Revision 4 LS-AA-1400, Event Reporting Guidelines, Revision 2 LS-MW-1340, Reportable Events, ENV, Revision 4 40 CFR 302, Designation, Reportable Quantities, and Notification 40 CFR 141, National Primary Drinking Water Regulations 35 IAC 611, Primary Drinking Water Standards 35 IAC 620, Groundwater Quality 81
 
Attachment 10 Page 1 of 14 Summary of Applicable State, Federal, and Offsite Dose Calculation Manual (ODCM) Regulations and Requirements for Tritium Releases to the Environment TITLE 35: ENVIRONMENTAL PROTECTION SUBTITLE F: PUBLIC WATER SUPPLIES CHAPTER I: POLLUTION CONTROL BOARD PART 620.410 GROUNDWATER QUALITY Effective November 25, 1991Class I: Potable Groundwater e) Beta Particle and Photon Radioactivity
: 1) Except due to natural causes, the average annual concentration of beta particle and photon radioactivity from man-made radionuclides shall not exceed a dose equivalent to the total body organ greater than 4 norem/year in Class I groundwater. If two or more radionuclides are present, the sum of their dose equivalent to the total body, or to any internal organ shall not exceed 4 mrem/year in Class I groundwater except due to natural causes.
: 2) Except for the radionuclides listed in subsection (e)(3), the concentration of man-made radionuclides causing 4 mrem total body or organ dose equivalent must be calculated on the basis of a 2 liter per day drinking water intake using the 168-hour data in accordance with the procedure set forth in NCRP Report Number 22, incorporated by reference in Section 620.125(a).
: 3) Except due to natural causes, the average annual concentration assumed to produce a total body or organ dose of 4 mrem/year of the following chemical constituents shall not be exceeded in Class I groundwater:
Critical Standard Constituent              Organ                  (pCi/L)
Tritium                Total body              20,000.0 Strontium-90            Bone marrow            8.0 82
 
Attachment 10 Page 2 of 14 ODCM Appendix A Revision 3 January 2002 A.2.2 Liquid Effluent Concentrations Requirement Requirement One method of demonstrating compliance to the requirements of 10 CFR 20.1301 is to demonstrate that the annual average concentrations of radioactive material released in gaseous and liquid effluents do not exceed the values specified in 10 CFR 20 Appendix B, Table 2, Column 2. (See 10 CFR 20.1302(b)(2).)
However, as noted in Section A.5.1, this mode of 10 CFR 20.1301 compliance has not been elected.
[Mode of compliance selected is as follows:]
As a means of assuring that annual concentration limits will not be exceeded, and as a matter of policy assuring that doses by the liquid pathway will be ALARA; RETS provides the following restriction:
"The concentration of radioactive material released in liquid effluents to unrestricted areas shall be limited to ten times the concentration values in Appendix B, Table 2, Column 2 to 10 CFR 20.1001-20.2402."
This also meets the requirement of Station Technical Specifications and RETS.
A.2.4 Tank Overflow Requirement To limit the consequences of tank overflow, the RETS/Technical Specifications may limit the quantity of radioactivity that may be stored in unprotected outdoor tanks. Unprotected tanks are tanks that are not surrounded by liners, dikes, or walls capable of holding the tank contents and that do not have tank overflows and surrounding area drains connected to the liquid radwaste treatment system. The specific objective is to provide assurance that in the event of an uncontrolled release of a tank's contents, the resulting radioactivity concentrations beyond the unrestricted area boundary, at the nearest potable water supply and at the nearest surface water supply, will be less than the limits of 10 CFR 20 Appendix B, Table 2; Column 2.
The Technical Specifications and RETS may contain a somewhat similar provision. For most nuclear power stations, specific numerical limits are specified on the number of curies allowed in affected tanks.
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Attachment 10 Page 3 of 14 A.2.5 Operability and Use of the Liquid Radwaste Treatment System Requirement The design objectives of 10 CFR 50, Appendix I and RETS/Technical Specifications require that the liquid radwaste treatment system be operable and that appropriate portions be used to reduce releases of radioactivity when projected doses due to the liquid effluent from each reactor unit to restricted area boundaries exceed either of the following (see Section 12.3 of each station's RETS or Technical Specifications);
* 0.06 mrem to the total body in a 31 day period.
* 0.2 mrem to any organ in a 31 day period.
A.2.6 Drinking Water Five nuclear power stations (Braidwood, Dresden, LaSalle, Quad Cities, and Zion) have requirements for calculation of drinking water dose that are related to 40 CFR 141, the Environmental Protection Agency National Primary Drinking Water Regulations. These are discussed in Section A.6.
A.6      DOSE DUE TO DRINKING WATER (40 CFR 141)
The National Primary Drinking Water Regulations, 40 CFR 141, contain the requirements of the Environmental Protection Agency applicable to public water systems. Included are limits on radioactivity concentration. Although these regulations are directed at the owners and operators of public water systems, several stations have requirements in their Technical Specifications related to 40 CFR 141.
A.6.1 40 CFR 141 Restrictions on Manmade Radionuclides Section 141.16 states the following (not verbatim):
(a)    The average annual concentration of beta particle and photon radioactivity from man-made radionuclides in drinking water shall not produce an annual dose equivalent to the total body or any internal organ greater than 4 millirem/year.
(b)    Except for the radionuclides listed in Table A-0, the concentration of man-made radionuclides causing 4 mrem total body or organ dose equivalents shall be calculated on the basis of drinking 2 liter of water per day. (Using the 168 hour data listed in "Maximum Permissible Body Burdens and Maximum Permissible Concentration of Radionuclides in Air or Water for Occupational Exposure, "NBS Handbook 69 as amended August 1963, U.S. Department of Commerce.). If two or more radionuclides are present, the sum of their annual dose equivalents to the total body or any organ shall not exceed 4 milliremlyear.
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Attachment 10 Page 4 of 14 TABLE A-0 AVERAGE ANNUAL CONCENTRATIONS ASSUMED TO PRODUCE A TOTAL BODY OR ORGAN DOSE OF 4 MREM/YR Radionuclide          Critical Organ          pCi / liter Tritium              Total body          20,000 Strontium-90          Bone marrow                8 LIQUID EFFLUENTS Chapter 12 Revision 7 September, 2002 12.3.1  Concentration Operability Requirements 12.3.1.A        The concentration of radioactive material released in liquid effluents to UNRESTRICTED AREAS (see Braidwood Station ODCM Annex, Appendix F, Figure F-i) shall be limited to 10 times the concentration values in Appendix B, Table 2, Column 2 to 10 CFR 20.1001-20.2402, for radionuclides other than dissolved or entrained noble gases. For dissolved or entrained noble gases, the concentration shall be limited to 2x10-4 microCurie/mI total activity.
Applicability: At all times Action:
1t      With the concentration of radioactive material released in liquid effluents to UNRESTRICTED AREAS exceeding the above limits, immediately restore the concentration to within the above limits.
Surveillance Requirements 12.3.1.B.1      Radioactive liquid wastes shall be sampled and analyzed according to the sampling and analysis program of Table 12.3-1.
12.3.1.B.2      The results of the radioactivity analysis shall be used in accordance with the methodology and parameters in the ODCM to assure that the concentrations at the point of release are maintained within the limits of 12.3.1.A.
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Attachment 10 Page 5 of 14 Bases 12.3.1.C This section is provided to ensure that the-concentration of radioactive materials released in liquid waste effluents to UNRESTRICTED AREAS will be less than 10 times the concentration values in Appendix B, Table 2, Column 2 to 10 CFR 20.1001-20.2402. This limitation provides additional assurance that the levels of radioactive materials in bodies of water in UNRESTRICTED AREAS will result in exposures within: (1) the Section II.A design objectives of Appendix 1,10 CFR 50, to a MEMBER OF THE PUBLIC, and (2) the limits of 10 CFR 20.1301.
This section applies to the release of radioactive materials in liquid effluents from all units at the site.
The required detection capabilities for radioactive materials in liquid waste samples are tabulated in terms of the lower limits of detection (LLDs). Detailed discussion of the LLD, and other detection limits can be found in HASL Procedures Manual, HASL-300 (revised annually), Currie, L.A., "Limits for Qualitative Detection and Quantitative Determination -
Application to Radiochemistry," Anal. Chem. 40, 586-93 (1968), and Hartwell, J.K.,
        "Detection Limits for Radioana!ytical Counting Techniques," Atlantic Richfield Hanford Company Report ARH-SA-21 5 (June 1975).
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Attachment 10 Page 6 of 14 TABLE 12.3-1 RADIOACTIVE LIQUID WASTE SAMPLING AND ANALYSIS PROGRAM LIQUID RELEASE        SAMPLING      MINIMUM ANALYSIS            TYPE OF ACTIVITY        LOWER, LIMIT OF TYPE          FREQUENCY          FREQUENCY                    ANALYSIS          DETECTION (LLD)(')
(PiCVmI)
I. Batch Release            P                P              Principal Gamma Emitters(7)      5x10-7 Tanks(2)            Each Batch        Each Batch 1-131                            1xi 0. 6 P                M              Dissolved and Entrained          1x10"5 One Batch/M                            Gases (Gamma Emitters)
P                M              H-3                              1xi 0 5 Each Batch        Composite  (3) 7 Gross Alpha                      1x1 0-P                Q              Sr-89, Sr-90                      5x1 0-8 Each Batch        Composite (3)
Fe-55                            lxi 06 7
: 2. Continuous                                  W              Principal Gamma Emitters(7)      5x1 0 Releases (4)        Continuous(s)      Composite(5) 1-131                            1x10s6
: a. Circulating Water        M                M              Dissolved and Entrained          lx10 5 Blowdown            Grab Sample                            Gases (Gamma Emitters) 5
: b. Waste Water                                M                          H-3                  1x10*
Treatment          Continuous(5)      Coin posite(5 )
Discharge to Circulating Water Discharge 7
Gross Alpha              1x1 0
: c. Condensate        Continuous(5 )          Q    5        Sr-89, Sr-90                      5x1 0.8 Polisher Sump                        Composite( )
Discharge 6
Fe-55                            1x10 87
 
Attachment 10 Page 7 of 14 TABLE 12.3-1 (Continued)
RADIOACTIVE LIQUID WASTE SAMPLING AND ANALYSIS PROGRAM LIQUID RELEASE    SAMPLING  MINIMUM ANALYSIS      TYPE OF ACTIVITY LOWER LIMIT OF TYPE      FREQUENCY      FREQUENCY              ANALYSIS      DETECTION (LLD)(1)(PCi/mI)
: 3. Continuous            W(6)          W(6)          Principal Gamma        5x10-7 Release(4)        Grab                        Emitters(7)
Essential        Sample Service Water Reactor Containment Fan Cooler (RCFC) Outlet Line 1-131                    x10"6 H-3                    lx10-5 M (6)        Dissolved and          1x10.5 Entrained Gases (Gamma Emitters)
: 4. Continuous          None          None          Principal Gamma        5x10-7 Surge Tank                                          Emitters(7)
Vent-Component Cooling Water Line (8)
Dissolved and          I xl0 5 Entrained Gases (Gamma Emitters) 1-131                  1xl 0-6 88
 
Attachment 10 Page 8 of 14 TABLE 12.3-1 (Continued)
RADIOACTIVE LIQUID WASTE SAMPLING AND ANALYSIS PROGRAM TABLE NOTATIONS (1) The LLD is defined, for purposes of these sections, as the smallest concentration of radioactive material in a sample that will yield a net count, above system background, that will be detected with 95% probability with only 5% probability of falsely concluding that a blank observation represents a "real" signal.
For a particular measurement system, which may include radiochemical separations:
LLD =              4.66sh E x V x 2.22 x10 6 x Y x exp (-XAt)
Where:
LLD = the lower limit of detection (microCuries per unit mass or volume),
Sb  = the standard deviation of the background counting rate or of the counting rate of a blank sample as appropriate (counts per minute),
E = the counting efficiency (counts per disintegration),
V = the sample size (units of mass or volume),
2.22 X1i06 = the number of disintegrations per minute per microCurie, Y  = the fractional radiochemical yield, when applicable, k  = the radioactive decay constant for the particular radionuclide (sec .), and At = the elapsed time between the midpoint of sample collection and the time of counting (sec).
Typical values of E, V, Y, and At should be used in the calculation.
Alternative LLD Methodology An alternative methodology for LLD determination follows and is similar to the above LLD              equation:
LLD = (2.71 + 4.654/B) x Decay E x q x b x Y x t (2.22 X10 6 )
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Attachment 10 Page 9 of 14 TABLE 12.3-1 (Continued)
RADIOACTIVE LIQUID WASTE SAMPLING AND ANALYSIS PROGRAM TABLE NOTATIONS Where:
B = background sum (counts)
E = counting efficiency, (counts detected/disintegration's) q = sample quantity, (mass or volume) b = abundance, (if applicable)
Y = fractional radiochemical yield or collection efficiency, (if applicable) t = count time (minutes) 2.22X106 = number of disintegration's per minute per microCurie 2.71 + 4.65B= k2 + (2k q/2 q B), and k = 1.645.
(k=value of the t statistic from the single-tailed t distribution at a significance level of 0.95 and infinite degrees of freedom. This means that the LLD result represents a 95% detection probability with a 5% probability of falsely concluding that the nuclide present when it is not or that the nuclide is not present when it is.)
Decay = e&#xfd;t [XRT/(1 -eXRm)] [XT,(1 -e'Td)], (if applicable)
X = radioactive decay constant, (units consistent with At, RT and        Td)
At = "delta t', or the elapsed time between sample collection or the midpoint of sample collection and the time the count is started, depending on the type of sample, (units consistent with X)
RT= elapsed real time, or the duration of the sample count, (units consistent with k)
Td = sample deposition time, or the duration of analyte collection onto the sample                media',
(units consistent with X)
The LLD may be determined using installed radioanalytical software, if available. In addition to determining the correct number of channels over which to total the background sum, utilizing the software's ability to perform decay corrections (i.e. during sample collection, from sample collection to start of analysis and during counting), this alternate method will result in a more accurate determination of the LLD.
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Attachment 10 Page 10 of 14 It should be recognized that the LLD is defined as a before the fact limit representing the capability of a measurement system and not as an after the fact limit for a particular measurement.
TABLE 12.3-1 (Continued)
RADIOACTIVE LIQUID WASTE SAMPLING AND ANALYSIS PROGRAM TABLE NOTATIONS (2)    A batch release is the discharge of liquid wastes of a discrete volume. Prior to sampling for analyses, each batch shall be isolated, and then thoroughly mixed to assure representative sampling.
(3)    A composite sample is one in which the quantity of liquid sampled is proportional to the quantity of liquid waste discharged and in which the method of sampling employed results in a specimen that is representative of the liquids released.
(4)    A continuous release is the discharge of liquid wastes of a nondiscrete volume, e.g., from a volume of a system that has an input flow during the continuous release.
(5)    To be representative of the quantities and concentrations of radioactive materials in liquid effluents, samples shall be collected continuously whenever the effluent stream is flowing. Prior to analyses, all samples taken for the composite shall be thoroughly mixed in order for the composite sample to be representative of the effluent release.
(6)    Not required unless the Essential Service Water RCFC Outlet Radiation Monitors RE-PRO02 and RE-PRO03 indicates measured levels greater than lx1 06 gCi/ml above background at any time              during the week.
(7)    The principal gamma emitters for which the LLD specification applies include the following radionuclides:
Mn-54, Fe-59, Co-58, Co-60, Zn-65, Mo-99, Cs-1 34, Cs-1 37, and Ce-141. Ce-144 shall also be measured, but with an LLD of 5E-06. This list does not mean that only these nuclides are to be considered.
Other gamma peaks that are identifiable, together with those of the above nuclides, shall also be analyzed and reported in the Radioactive Effluent Release Report pursuant to Section 12.6.2, in the format outlined in Regulatory Guide 1.21, Appendix B, Revision 1, June 1974.
(8)    A continuous release, is the discharge of dissolved and entrained gaseous waste from a nondiscrete liquid volume.
12.3.2 Dose Operability Requirements 12.3.2.A The dose or dose commitment to a MEMBER OF THE PUBLIC from radioactive materials in liquid effluents released, from each unit, to UNRESTRICTED AREAS (see Braidwood Station ODCM Annex, Appendix F, Figure F-i) shall be limited:
: 1. During any calendar quarter to less than or equal to 1.5 mrems to the whole body and to less than or equal to 5 mrems to any organ, and
: 2. During any calendar year to less than or equal to 3 mrems to the whole body and to less than or equal to 10 mrems to any organ.
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Attachment 10 Page 11 of 14 Applicability: At all times.
Action:
: 1. With the calculated dose from the release of radioactive materials in liquid effluents exceeding any of the above limits, prepare and submit to the Commission within 30 days, pursuant to 10 CFR 50 Appendix I, Section IV.A, a Special Report that identifies the cause(s) for exceeding the limit(s) and defines the corrective actions that have been taken to reduce the releases and the proposed corrective actions to be taken to assure that subsequent releases will be in compliance with the above limits.
Surveillance Requirements 12.3.2.B Cumulative dose contributions from liquid effluents for the current calendar quarter and the current calendar year shall be determined in accordance with the methodology and parameters in the ODOM at least once per 31 days.
Bases 12.3.2.C This section is provided to implement the requirements of Sections II.A, Ili.A and IV.A of Appendix 1,10 CFR 50. The Operability Requirements implement the guides set forth in Section II.A of Appendix I. The ACTION statements provide the required operating flexibility and at the same time implement the guides set forth in Section IV.A of Appendix I to assure that the releases of radioactive material in liquid effluents to UNRESTRICTED AREAS will be kept "as low as is reasonably achievable." The dose calculation methodology and parameters in the ODCM implement the requirements in Section Ili.A of Appendix I that conformance with the guides of Appendix I be shown by calculational procedures based on models and data, such that the actual exposure of a MEMBER OF THE PUBLIC through appropriate pathways is unlikely to be substantially underestimated.
The equations specified in the ODCM for calculating the doses due to the actual release rates of radioactive materials in liquid effluents are consistent with the methodology provided in Regulatory Guide 1.109, "Calculation of Annual Doses to Man From Routine Releases of Reactor Effluents For the Purpose of Evaluating Compliance with 10 CFR 50, Appendix I" Revision 1, October 1977 and Regulatory Guide 1.113, "Estimating Aquatic Dispersion of Effluents from Accidental and Routine Reactor Releases for the Purpose of Implementing Appendix I," April 1977.
This section applies to the release of radioactive materials in liquid effluents from each reactor at the site. When shared Radwaste Treatment Systems are used by more than one unit on a site, the wastes from all units are mixed for shared treatment; by such mixing, the effluent releases cannot accurately be ascribed to a specific unit. An estimate should be made of the contributions from each unit based on input conditions, e.g., flow rates and radioactivity concentrations, or, if not practicable, the treated effluent releases may be allocated equally to each of the radioactive waste producing units sharing the Radwaste Treatment System. For determining conformance to Operability Requirements, these allocations from shared Radwaste Treatment Systems 92
 
Attachment 10 Page 12 of 14 are to be added to the releases specifically attributed to each unit to obtain the total releases per unit.
12.3.3 Liquid Radwaste Treatment System Operability Requirements 12.3.3.A The Liquid Radwaste Treatment System shall be OPERABLE and appropriate portions of the system shall be used to reduce releases of radioactivity when the projected doses due to the liquid effluent, from each unit, to UNRESTRICTED AREAS (see Braidwood Station ODCM Annex, Appendix F, Figure F-i) would exceed 0.06 mrem to the whole body or 0.2 mrem to any organ in a 31-day period.
Applicability: At all times.
Action:
: 1. With radioactive liquid waste being discharged without treatment and in excess of the above limits and any portion of the Liquid Radwaste Treatment System not in operation, prepare and submit to the Commission within 30 days, pursuant to 10 CFR 50 Appendix I, Section IV.A, a Special Report that includes the following information:
: a.        Explanation of why liquid radwaste was being discharged without treatment, identification of any inoperable equipment or subsystems, and the reason for the inoperability,
: b.        Action(s) taken to restore the inoperable equipment to OPERABLE status, and
: c.        Summary description of action(s) taken to prevent a recurrence.
Surveillance Requirements 12.3.3.B.1        Doses due to liquid releases from each unit to UNRESTRICTED AREAS shall be projected at least once per 31 days in accordance With the methodology and parameters in the ODCM when the Liquid Radwaste Treatment System is not being fully utilized.
12.3.3.B.2        The installed Liquid Radwaste Treatment System shall be considered OPERABLE by meeting Sections 12.3.1.A and 12.3.2.A.
Bases 12.3.3.C          The OPERABILITY of the Liquid Radwaste Treatment System ensures that this system will be available for use whenever liquid effluents require treatment prior to release to the environment. The requirement that the appropriate portions of this system be used when specified provides assurance that the releases of radioactive materials in liquid effluents will be kept "as low as is reasonably achievable". This section implements the requirements of 10 CFR 50.36a, General Design Criterion 60 of Appendix A to 10 CFR 50 and the design objective given in Section 11.D of Appendix I-to 10 CFR 50.
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Attachment 10 Page 13 of 14 The specified limits governing the use of appropriate portions of the Liquid Radwaste Treatment System were specified as a suitable fraction of the dose design objectives set forth in Section II.A of Appendix 1, 10 CFR 50, for liquid effluents.
This section applies to the release of radioactive materials in liquid effluents from each unit at the site. When shared Radwaste Treatment Systems are used by more than one unit on a site, the wastes from all units are mixed for shared treatment; by such mixing, the effluent releases cannot accurately be ascribed to a specific unit. An estimate should be made of the contributions from each unit based on input conditions, e.g., flow rates and radioactivity concentrations, or, if not practicable, the treated effluent releases may be allocated equally to each of the radioactive waste producing units sharing the Radwaste Treatment System.
For determining conformance to Operability Requirements, these allocations from shared Radwaste Treatment Systems are to be added to the releases specifically attributed to each unit to obtain the total releases per unit.
Radiological Environmental Monitoringq Program (REMP)
Braidwood ODCM Table 12.5-1 section 3.a, Ground / well water specifies that samples from two sources are required only if they are likely to be affected. Note (6) of ODCM Table 12.5-1 clarifies that groundwater samples shall be taken when this source is tapped for drinking or irrigation purposes in areas where the hydraulic gradient or recharge properties are suitable for contamination. Per discussion with Conestoga-Rovers & Associates and the Exelon Hydrologist, onsite groundwater at Braidwood meets the above criteria. There are drinking water wells in close proximity of the site that could be affected. However, there are no specific groundwater sample locations identified in the REMP. This requirement should be reviewed to determine the groundwater monitoring required to meetthe requirements of Table 12.5-1.
Review of Braidwood ODCM Table 11-1 section 3.a, Ground / well water indicates that there are (5) drinking water wells currently being monitored.
Braidwood ODCM Table 12.5-1 Section 3.a and note (6) to the table discusses the need for groundwater monitoring when the irrigation pathway is a credible pathway. The hydraulic gradient at Braidwood indicates that shallow wells could become contaminated. ODCM Section 4.3 states that the only liquid pathways used are the potable water and fish ingestion pathways. The irrigation to food crop pathway associated with the groundwater contamination should be evaluated. (CAll)
Monitoring for other nuclides 40 CFR 141 and 35 IAC 620 specify limits on radionuclides other than tritium. As part of Braidwood's recovery plan, gamma-emitting fission and activation products as well as other beta-emitting nuclides (Strontium-89, and Strontium-90) are being analyzed. The gamma-emitting nuclide analytical results indicate normal background levels. Strontium-89 and Strontium-90 results indicate normal background levels.
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Attachment 10 Page 14 of 14 Generic Chapters Revision 3 January, 2002 Table 2-1 Regulatory Dose Limit Matrix REGULATION                              DOSE TYPE                        DOSE LIMIT(s) 3              ODCM EQUATION Liquid Releases:                                                          (quarterly)      (annual) 10 CFR 50 App. V3          Whole (Total) Body Dose                          1.5 mrem        3 mrem          A-17 (per reactor unit)
Organ Dose (per reactor unit)                    5 mrem        10 mrem          A-17 Technical Specifications  The concentration of radioactivity in liquid  Ten (10) times the effluents released to unrestricted areas      concentration values listed        A-21 in 10 CFR 20 Appendix B; Table 2, Column 2, Table C-6 of ODCM Appendix C for Noble Gases Total Doses 1:
10 CFR 20.1301 (a)(1)      Total Effective Dose Equivalent 4                      100 mrem/yr              A-25 10 CFR 20.1301 (d)        Total Body Dose                                        25 mrem/_yr              A-25 and 40 CFR 190            Thyroid Dose                                            75 mrem/yr                A-25 Other Organ Dose                                        25 mrem__/yr              A-25 Other Limits      2:
40 CFR 141                Total Body Dose Due to Drinking Water From              4 mrem/yr                A-17 Public Water Systems Organ Dose Due to Drinking Water From                    4 mrem/yr                A- 17 Public Water Systems 1 These doses are calculated considering all sources of radiation and              radioactivity in effluents.
2 These limits are not directly applicable to nuclear power stations.              They are applicable to the owners or operators of public water systems. However, the RETS of some of the Exelon Nuclear power stations require assessment of compliance with these limits. For additional information, see Section A.6 of Appendix A.
3  Note that 10 CFR 50 provides design objectives not limits.
4  Compliance with 10 CFR 20.1301(a)(1) is demonstrated by compliance with 40 CFR 190. Note that it may be necessary to address dose from onsite activity by members of the public as well.
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Attachment 11 Root Cause Report Quality Checklist
                                                        .Page 1 of 2.
A. Critical Content Attributes                                        YES NO
: 1. Is the condition that requires resolution adequately and accurately identified?                                            X
: 2. Are inappropriate actions and equipment failures (causal factors) identified?                                              X
: 3. Are the causes accurately identified, including root causes and contributing causes?                                              X
: 4. Are there corrective actions to prevent recurrence identified for each root cause and do they tie DIRECTLY to the root cause?
AND, are there corrective actions for contributing cause and do    X they tie DIRECTLY to the contributing cause?
: 5. Have the root cause analysis techniques been appropriately used and documented?                                                X
: 6. Was an Event and Causal Factors Chart properly prepared?            X
: 7. Does the report adequately and accurately address the extent of condition in accordance with the guidance provided in              X Attachment 3 of LS-AA-125-1003, Reference 4.3?
: 8. Does the report adequately and accurately address plant specific risk consequences?                                        X
: 9. Does the report adequately and accurately address programmatic and organizational issues?                            X
: 10. Have previoussimilar events been evaluated? Has an Operating Experience database search been performed to determine whether the problem was preventable if industry experience          X had been adequately implemented?
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Attachment 11 Root Cause Report Quality Checklist Page 2 of 2 B. Important Content Attributes
: 1. Are all of the important facts included in the report?            X
: 2. Does the report explain the logic used to arrive at the            X conclusions?
: 3. If appropriate, does the report explain what root causes were      X considered, but eliminated from further consideration and the bases for their elimination from consideration?
: 4. Does the report identify contributing causes, if applicable?      X
: 5. Is it clear what conditions the corrective actions are intended to X create?
: 6. Are there unnecessary corrective actions that do not address the    X root causes or contributing causes?
: 7. Is the timing for completion of each corrective action            X commensurate with the importance or risk associated with the issue?
C. Miscellaneous Items
: 1.                Did an individual who is qualified in Root Cause      X Analysis prepare the report?
: 2.                Does the Executive Summary adequately and            X accurately describe the significance of the event, the event sequence, root causes, corrective actions, reportability, and previous events?
: 3.                Do the corrective actions include an effectiveness    X review for corrective actions to prevent recurrence?
: 4.                  Were ALL corrective actions entered and verified to  X be in Action Tracking?            "
: 5.                  Are the format, composition, and rhetoric acceptable  X (grammar, typographical errors, spelling, acronyms, etc.)?
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Attachment 12 Vacuum Breaker #3 (VB-3) and Vacuum Breaker 2 (VB-2)
Event Timeline Page l of 13 Vacuum Breaker #3 (VB-3)
December 1997
* VB-3 was inspected (PM 00079293) with no water leakage noted.
December, 3 to 4, 1998 VB-3 was discovered leaking, due to water hammer failure of the air vent valve line (RC 38237-02). The Problem Identification Form (PIF) for this event (A1998-04324) was closed to no concern, based on the water being contained onsite and apparently personnel not aware of a tritium concern (Root Cause 4). The PIF stated that the water was in the ditch, which Exelon owns. PIF A1998-04324 stated the repair (temporary) to stop the leak was completed within 24 hours (12/05/1998) under WO 98127749. This section of ditch is blocked at both ends. The size/amount of leakage was not recorded due to a lack of monitoring instrumentation (Other Issue "a"), but was estimated in 2000 to be similar to the 2000 VB-2 leakage at approximately 3 million gallons over a 30-day period. No integrated spill response procedure was in place to guide adequate station response. ( Root Cause 3)
December 1998 Spill Conclusion In 1998, VB-3 failed and released approximately three million gallons producing standing surface water on Braidwood property.          Problem Identification Form (PIF) A1998-04324
[equivalent to today's Issue Report (IR)] was created to document and address this spill. The response to this event was to isolate the valve and repair the valve as soon as possible. The Braidwood NPDES Coordinator was notified and determined that there were no environmental concerns because the water had not reached a waterway. The environmental procedures concentrate on NPDES compliance associated with oil or hazardous materials and by design, provide no guidance on radiological spills (Failed Barriers 1 & 2).
The Reportability Manual (LS-AA-1 020 & 1110) does not reflect ODCM REMP/RETS reporting requirements for unplanned release paths (Faile.d Barriers 7-11). Also, these procedures do not reflect 35 IAC 620 groundwater tritium requirements (Failed Barriers 7-11). At the time, Operations personnel believed (through interviews) that the water leaking from the CW B/D VB was procedurally treated and approved for radiological release to the environment (Kankakee River) and they assumed it to be radiologically acceptable if it leaked to the ground.
Engineering interviews indicated that they were aware of diluted radioactive waste effluent in the CW B/D line, but since there had been no training for the requirements or the implications of a CW B/D water spill, the creation of a work request and issue report would be an adequate response to correct the leak during the next scheduled work week.
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Attachment 12 Vacuum Breaker,#3 (VB-3) and Vacuum Breaker 2 (VB-2)
Event Timeline Page 2 of 13 The Event Screening Committee (the equivalent of today's Braidwood Senior Management Review Committee) reviewed PIF A1998-04324 and assigned no actions to inquire into or address radiological concerns. As a consequence, no action items were created to track the characterization, remediation and documentation of this spill. Radiological concerns were not recognized. There was no documentation that any spill remediation was performed. A root cause for the ineffective response was weak management review and oversight of spill response activities (Root Cause 4). In this event , the knowledgeable personnel with the radiological expertise were not brought to bear. The root cause was determined to be a lack of integrated procedural guidance to ensure proper recognition, evaluation, and timely mitigation of the spill events (Root Cause 3) to ensure proper identification, timely mitigation and evaluation of the spill events, including knowledge of local hydrology, the impact of low-level tritium leaks, and groundwater regulations.
Documentation associated with the response does not indicate recognition that a potential radioactive spill had occurred. Had it been recognized that the 1998 release of tritium to an unplanned location (the field in the vicinity of VB-3) was a radiological release, a more rigorous characterization and remediation response may have been initiated. A lack of recognition by the Operations Department personnel (who initiate and secure the release of processed radioactive waste into the CW B/D System) and/or the Radiological Protection personnel (who sample and analyze the release tanks prior to concurring with the release), would be a missed opportunity.
Additionally, the 1998 Annual Effluent Report did not contain an evaluation of the vacuum breaker radioactivity released and did not contain the associated evaluation of the dose to the public (IR 455079) & (CA-15). No documentation was located that implied a recognition of vacuum breaker leakage impact on the requirements of the ODCM, REMP, and 10CFR50.75(g).
The root cause of the large volume leaks in 1998 and 2000 is documented in Root Cause Report (RCR) 38237, which determined that the Circulating Water (CW) Blowdown (B/D)
Vacuum Breaker (VB) Valves had inadequate preventative maintenance programs and inadequate design configuration (Root Cause 1).
November 15, 2000 Condition Report (CR) A2000-04389 was written which stated that the 1998 response to PIF Al 998-04324 was inadequate, as a result of Root Cause Report (RCR) 38237/CR A2000-04281. CR A2000-04389 resulted in an action to Radiation Protection to perform a radiological evaluation under 10 CFR 50.75(g). June 18, 2001 99
 
Attachment 12 Vacuum Breaker #3 (VB-3) and Vacuum Breaker 2 (VB-2)
Event Timeline Page 3 of 13 CR A2001-01806 reported VB-3 leaking. WC-AA-106 did not have tritium concerns integrated into the work prioritization. At this time, there was no guidance in the CW B/D procedures to secure radiological releases when known leaks were discovered. (Root Cause 3)
Note: Little to no information could be found in PIF's or WR/WO's for this event.
Therefore, little data could be retrieved by this Root Cause Investigation Team (IR 428868) other than from personnel interviews.
July 21, 2001
* CR A2000-04389's 10 CFR        50.75(g) Radiological Assessment Report was completed based on samples obtained      in April 2001. In retrospect, the 1998 VB-3 spill site was inadequately characterized,    due to the lack of groundwater assessment for tritium concentrations. Therefore,    the evaluation erroneously concluded that there was no further action required.
July 23, 2001
* Revision 2 of WO 98127749 to repair VB-3 is authorized for work by Operations. The WO comments stated that leaking water prevented work completion. The WO did not contain precautions regarding tritium leakage, due to ATI 106767-04 (May 2002) comments not being incorporated into the WO. (OtherIssue "b")
December 2001
* VB-3 was inspected (WO 99284438) with no water leakage noted.
May 4, 2002
* VB-3 pilot (air release) valve seat was discovered leaking water. WO 004402131 and IR 106767 were written.
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Attachment 12 Vacuum Breaker #3 (VB-3) and Vacuum Breaker 2 (VB-2)
Event Timeline Page 4 of 13 May 20, 2002
* Revision 2 of WO 98127749 to repair the isolation valve for VB-3 was completed, with no mention of radiological controls for the water discovered in the vacuum breaker pit. (Root Cause 3)
August 29, 2003 Water was found in the VB-3 valve pit during walkdown surveillance. WR 00110407 and IR 173688 were written. The IR indicates water is most likely groundwater intrusion into the pit. There was no observed leakage from VB-3.
March 17, 2005 The Illinois Environmental Protection Agency (IEPA) contacted Exelon concerning an investigation of tritium concentrations in wells near Braidwood Station in preparation for the Godley public hearing. Sampling to investigate this report was commenced. (IR 328451)
November 30, 2005
* Issue Report (IR) 428868 reports tritium concentrations from what appears to be the area of the 1998 spill, have migrated offsite with a potential to affect the public via tritiated groundwater. (EVENT)
Vacuum Breaker 2 (VB-2)
December 1996
* VB-2 was inspected (PM 00079293) with no water leakage noted.
January 5, 1998
* Water leak discovered on the VB-2 pilot (air release) valve seat.      WR 9800691 was written.
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Attachment 12 Vacuum Breaker #3 (VB-3) and Vacuum Breaker 2 (VB-2)
Event Timeline Page 5 of 13 May 24, 2000
* VB-2-found leaking. Issue tracked via WR 9800691.
November 6, 2000 14:30 The Braidwood National Pollutant Discharge Elimination System (NPDES) Coordinator received a call from the Illinois Environmental Protection Agency (IEPA) regarding standing water in a ditch immediately adjacent to private property along the south side of Smiley Road. An area resident had reported the water and noted that the water had been present in the ditch for approximately 7-10 days prior to IEPA notification.
Suspecting a faulty vacuum breaker, the NPDES Coordinator notified the Shift Manager and Outage Control Center (OCC) Director of the IEPA notification.
November 6, 2000 15:00
* The Braidwood NPDES Coordinator walked down the Circulating Water Blowdown system and identified that the water was coming from a valve vault that houses VB-2.
The NPDES Coordinator assessed the site and concluded that the water was confined to site property which included the ditch along the south side of Smiley Road.
* The Braidwood NPDES Coordinator notified the IEPA of his findings regarding the water source and the boundaries of the discharge. Station NPDES monitoring requirements were discussed and the IEPA requested no additional sampling. The Braidwood NPDES Coordinator determined that there were no NPDES concerns since the water was contained and not discharging to "Waters of the State".
* The VB-2 leakage was estimated to be a maximum of 3 million gallons. This leakage was the result of corrosion of the vacuum breaker assembly and water hammer, which broke the float in VB-2, exposing an 8" opening.
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Attachment 12 Vacuum Breaker #3 (VB-3) and Vacuum Breaker 2 (VB-2)
Event Timeline Page 6 of 13 November 6, 2000 16:00 -17:00 A meeting was held with Braidwood Senior Management, the Shift Manager and the Outage Control Center (OCC) staff. The Braidwood NPDES Coordinator briefed the attendees on the results of his field observations of the area surrounding the vacuum breaker valve. Braidwood Senior Management was also briefed on the discussions between the Braidwood NPDES Coordinator and the IEPA.                Braidwood Senior Management directed the following actions be taken:
: 1.      Operating personnel were to evaluate water inventories and to explore potential alternate release options.
: 2.      Isolate the CW B/D system
: 3.      Make preparations to take the CW B/D system out of service, drain the piping section and replace the failed vacuum breaker valve.
The CW B/D system was then isolated in preparation for draining and repairs. There was no discussion at this time of any need to sample for radioactivity in the water that had been discharged. The thought process was that any radioactivity in the water had been diluted per procedure and was acceptable for discharge to the environment (i.e., the Kankakee River). [This is based on Operations Department personnel interviews.]
November 7, 2000 06:15
    , The Braidwood Operations Manager notified the Braidwood Radiation Protection (RP)
Manager that there was a blowdown line leak and that RP was to meet with the Braidwood Chemistry Manager to look at potential alternate radioactive release paths.
The reason for this request was that radioactive releases would not be possible via the blowdown system while blowdown was isolated for repairs to VB-2.
* Following this phone conversation, the Braidwood RP Manager notified the Braidwood RP Technical Superintendent regarding the need to collect samples of available water.
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Attachment 12 Vacuum Breaker #3 (VB-3) and Vacuum Breaker 2 (VB-2)
Event Timeline Page T7of 13 November 7, 2000 08:00 A decision to conduct confirmatory sampling of the water leaking from the manway cover of the vacuum breaker structure was made. The sample was taken at approximately 0845 and the results of the gamma isotopic analysis indicated no detectable radioactivity. Isotopic analysis indicated no detectable tritium.
* Braidwood chemistry manager contacts corporate environmental and asks them to report to the site to help assess the event.
Decision is made by Braidwood Senior Management to sample both soil and water at the vacuum breaker.
November 7, 2000 08:30 Mechanical Maintenance Department (MMD) personnel with assistance from System Engineering pumped out the VB-2 vault back into the B/D line and began draining the blowdown piping to facilitate work on VB-2.
November 7, 2000    11:30 Braidwood RP received information that the leak may have occurred for a period of 7-10 days and that the water that leaked was from the circulating water blowdown line, which carries the liquid radiological discharges from the station to the river.
November 7, 2000    12:00
* After the CW B/D line had drained sufficiently, the entire VB-2 isolation valve and vacuum breaker assembly was replaced.
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Attachment 12 Vacuum Breaker #3 (VB-3) and Vacuum Breaker 2 (VB-2)
Event Timeline Page8of 13a November 7, 2000    12:30
* A decision was made to initiate soil sampling in the vicinity of the vacuum breaker structure, and to obtain a water sample from the standing water that was onsite, but near the Smiley Road ditch.
November 7, 2000 13:00
* Braidwood RP Manager and Station Manager discuss and agree to additional sampling.
Plan was approved.
November 7, 2000 18:00
* Braidwood management talked with local residents to explain the issue.
November 7, 2000 19:00
* The results of the samples from November 7, 2000, were discussed with corporate Generation Support Department (GSD) RP Manager. Corporate GSD agreed to discuss the issue with the corporate GSD General Manager.
November 7, 2000 19:45
* The Station Manager and Site Vice-President (VP) were notified of the sample results. A total of 5 soil samples were obtained within approximately 30 feet of the vacuum breaker VB-2 structure, and 2 of the 5 soil samples had detectable levels of radioactivity. The onsite soil sample obtained near the Smiley Road ditch was analyzed indicated no gamma radioactivity, and water analysis from the location indicated tritium at 35,000 pCi/L.
November 7, 2000 21:15
* Circ water blowdown is restored.
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Attachment 12 Vacuum Breaker #3 (VB-3) and Vacuum Breaker 2 (VB-2)
Event Timeline Page9of 13 November 8, 2000 08:30
* The Braidwood RP Manager discussed the sample results on the morning call.
November 8, 2000 14:00
* The Braidwood RP Manager, Chemistry Manager, Regulatory Assurance Manager, Station Manager, and Site VP met to discuss the current status, next steps, and sampling for the event.
November 8, 2000 16:00 Additional onsite sampling of the standing water in the area leading to the Smiley Road ditch was performed. Four water samples were taken and results indicated tritium levels ranging from 35,000 to 53,000 pCi/L. No gamma isotopic activity was detected in the water.
November 8, 2000 18:00
* Conference call between site and corporate regarding test results and proposed actions.
November 9, 2000 10:00 A conference call was held with the Site Management and Corporate Personnel to finalize and approve an Offsite Sampling Plan, a Remediation Plan, and a Communications Plan. At 12:00, discussions were held with site and regional NRC personnel. At 1210, notification of the offsite release was made to Will County authorities and to the Reed Township Highway Commissioner. At 12:45, RP was dispatched to obtain water samples from the Smiley Road ditch.
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Attachment 12 Vacuum Breaker #3 (VB-3) and Vacuum Breaker 2 (VB-2)
Event Timeline Page 10 of 13 November 9, 2000    14:00 Four water samples were obtained from the Smiley Road ditch. Gamma isotopic analysis indicated and the tritium analyses ranged from 19,000 pCi/L to 25,000 pCi/L NQPF.
Teledyne Isotopes Midwest Laboratory also analyzed these samples with similar results.
November 9, 2000 17:30
* The NRC Regional Office and Illinois Department of Nuclear Safety (IDNS) were notified of the Smiley Road ditch sample analyses results.
November 10, 2000 01:00
* IDNS came to the site to take (4) samples from the Smiley Road ditch.
November 10, 2000 11:00
* Pumping of the water back to the blowdown line commenced. Pumping continued using a 600 gpm pump, approximately 18 hours per day.
* Corporate led remediation team formed and OP-AA-101-503 "NGG Issue Management Worksheet" was entered. Attachment 2 (action plan) of this procedure was created and approved.
November 2000 Spill Conclusions In 2000, VB-2 failed and released approximately three million gallons to the Braidwood Station grounds. A local resident observed and reported the spill to the Illinois Environmental Protection Agency (IEPA), who in turn notified the Braidwood Station National Pollutant Discharge Elimination System (NPDES) Coordinator. The NPDES Coordinator wrote PIF A2000-04281 and notified the Illinois Department of Nuclear Safety (IDNS), the Illinois Emergency Management Agency (IEMA) and Braidwood Senior Management. The Braidwood Radiation Protection (RP) Manager and the RP Technical Superintendent discussed the need to collect samples of available water at VB-2. The sample results indicated >20,000 pCi/L tritium was present in the spilled water. The immediate response to this event was to shutdown the blowdown system, repair the valve as soon as possible, and engage Senior Corporate Management to create a spill response plan.
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Attachment 12 Vacuum Breaker #3 (VB-3) and Vacuum Breaker 2 (VB-2)
Event Timeline Page 11 of 13 A Senior Corporate Manager was chosen to assemble and direct an Issues Management Team (IMT). Although knowledgeable personnel supported the IMT, there was no integrated procedure in place to ensure that all necessary actions were completed (Root Cause 3). As a result, the groundwater tritium was not properly characterized and remediated.
The IMT entered four (4) Corporate procedures, which provide guidance to identify, evaluate, remediate and communicate the radiological concerns. The four (4) procedures were:
* NSP-RP-61 01, "10 CFR 50. 75(g)(1) Documentation Requirements" 0  CWPI-NSP-1 -1, "CAP Process Manual of Common Work Practice Instructions -
Instruction on Event Response Guidelines'
* OP-AA-1 01-501, "NGG Significant Event Reporting' 0  OP-AA-1 01-503, "NGG Issues Managemenf'.
However, no historical documentation could be located to demonstrate that the procedures (other than NSP-RP-61 01) were fully executed. There is no evidence of the use of Passport for the documentation of the IMT plans and activities as required by OP-AA-101-503, "NGG Issues Management". This root cause team interviewed (by telephone) the Corporate Senior Manager who was assigned to manage the Issues Management Team. He was questioned concerning the execution of the IMT's responsibilities. The Corporate Senior Manager had little recollection of the details of the team's response. Although that Corporate Senior Manager had the responsibility to manage the IMT's completion of characterization and remediation plans and would normally be held accountable, he is no longer employed by Exelon. This indicates weak management review and oversight of spill response activities. (Root Cause 4)
The IMT developed separate soil sampling plans and water sampling plans flowcharts (decision trees). For soil, all documentation was done within the station 10 CFR 50.75(g) procedure, NSP-RP-6101. For water, the sampling plan included a review of the tritium in the water and implementation of a Remediation/Control Plan. Notes on the water sampling plan indicate that the team considered: 1) pumping the water back into the blowdown line and 2) well monitoring.
The IMT had also recognized the need to evaluate local hydrology for potential impact of the tritiated spill in groundwater as referenced in a contractor's proposal for the implementation of a Stage 1 and Stage 2 plan. Stage 1 included the installation of wells to assess the local hydrology to determine groundwater gradients and movement . This stage of the plan was executed by the IMT. Stage 2 of the plan included sampling of the groundwater to determine mixing model and surface infiltration into an aquifer. Stage 2 of the plan was not executed.
The water was pumped back into the B/D line on 11/10/00 and hydrology wells were installed in the area of the 2000 leak to characterize the local hydrology. The contractor report specified that the groundwater in the area of VB-2 would take 15 years to travel the 800 feet to reach the property line.
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Attachment 12 Vacuum Breaker #3 (VB-3) and Vacuum Breaker 2 (VB-2)
Event Timeline Page 12 of 13 The report then clarifies that the flow velocity would not apply to the surface water that apparently flowed from the valve box, over the land surface, and to the ditch along the road.
The remediation efforts were halted after the surface water was pumped back into the B/D line Although no documentation exists for the basis behind the decision to not perform groundwater sampling, a review of IMT data and, notes has lead the Root Cause Investigation Team to Conclude that the following information was considered in the decision making process:
* The spilled water had already been approved for release. Therefore, it was already determined to meet concentration limits for release to the public. The team assessed the impact of the radiological spill against known reporting requirements. The Illinois Groundwater statute was absent from the list in the IMT notes (Causal Factor 4).
* The hydrology study indicated that it would be. 15 years before groundwater in the area of VB-2 would migrate offsite to potentially impact offsite drinking water wells. At that rate, the tritium concentration would be below drinking water standards, potentially even below detectable levels, by the time it reached the site boundary due to radiological decay and, potentially, dilution. [Today, hydrology experts state that once the tritium enters the groundwater, dilution does not significantly occur.]
Further efforts included a 10 CFR 50.75(g) characterization study. The 2000 10 CFR 50.75(g) focused primarily on soil sampling. The 10 CFR 50.75(g) study does reference the tritium concentrations that were found in the standing water. The 10 CFR 50.75(g) study did not direct groundwater sampling for tritium nor assess the environmental impact of the spilled tritium (Failed Barrier 3). The 2000 RCR Team required an analysis of the 2000 leak 10 CFR 50.75(g) by an independent Certified Health Physicist and approval by Braidwood Senior Management, however, this analysis did not include tritium. As a result, the groundwater tritium went undetected until the 2005 tritium sampling discovered it. This indicates weak management review and oversight of spill response activities. (Root Cause 4)
The year 2000 leak from Vacuum Breaker (VB) 2, RCR # 38237 documented 5 CW B/D vacuum breaker spills. Two of these released a large volume of water. The root-cause of these leaks was inadequate preventative maintenance programs and inadequate design configuration (Root Cause 1). Effectiveness Review (EFR) of the Corrective Actions to Prevent Recurrence (CAPRs) of large volume leaks determined that the CAPRs were effective at resolving the Root Cause. However, the Root Cause was narrowly defined, only evaluating the large volume valve leaks and not considering radiological impacts from the spills due to a lack of technical rigor (CAPR 3 and CAPR 5 address this issue).
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Attachment 12 Vacuum Breaker #3 (VB-3) and Vacuum Breaker 2 (VB-2)
Event Timeline Page 13 of 13 The 2000 Root Cause Report (RCR) Team discovered the large volume 1998 VB-3 leak and wrote PIF A2000-04281 to have the 1998 spill reviewed per procedure # NSP-RP-6101 for residual radioactivity under 10 CFR 50.75(g). The soil sampling conducted as part of the 10 CFR 50.75(g) process indicated similar deposited radionuclides in the soil as that found during the 2000 leak. However, tritium was not addressed (Failed Barrier 3).
Braidwood Senior Management and Exelon Corporate Senior Management did not track characterization and mitigation plans to completion during and following the year 2000 spill.
Although the 2000 Annual Effluent Report did report the 2000 vacuum breaker leakage as an unplanned release, it did not contain a proper assessment of the dose to the public. The 1998 Annual Effluent Report was not amended to report the 1998 vacuum breaker leakage (discovered in 2000) and associated dose to the public (IR 455079) & (CA-15).
HU-AA-102 and -1212, Technical Human Performance Practices and Technical Task Risk/Rigor Assessment, Pre-Job Brief, Independent Third Party Review, and Post-Job Brief procedures have been instituted to improve technical rigor, questioning attitude, and attention to detail (CAPR 3). OP-AA-106-101-1002, Exelon Nuclear Issues Management, will be revised to: 1) improve Corrective Action Program (CAP) controls of Issue Management Teams, 2) utilize the tools and techniques of the Exelon HU-AA-102 and -1212, Technical Human Performance Practices and Technical Task Risk/Rigor Assessment, Pre-Job Brief, Independent Third Party Review, and Post-Job Brief procedures, 3) strengthen reporting requirements to station Senior Management, and 4) define station Senior Management responsibilities oversight and challenge of events and issues from initiation to final disposition (CAPR 5).
An email from an RP supervisor who attended an exit meeting for an NRC REMP (radiological effluent monitoring program) inspection (NRC Inspection Report Braidwood 2001-0005) provided the following information. The Nuclear Regulatory Commission (NRC) reviewed the 2000 Root Cause (RC 38237) (documented in NRC Inspection Report Braidwood 2001-0005) and had a recommendation to sample residential wells in the area of concern "just to see negative results from these locations to support future cleanup activities" (documented only in the email). A second comment from the NRC review was that the root cause only focused on the equipment issues and not on spill recovery aspects. No documentation could be found to show that the Issues Management Team or Braidwood Senior Management reacted to these NRC's observations. This response reflects a weak management review and oversight of spill response activities (Root Cause 4). A contributing cause to this overall event was a weak questioning attitude and an inadequate challenge culture by Braidwood Senior Management regarding the 17 CW B/D leaks over the 10 year period bridging 1996 to the present.
110}}

Revision as of 22:20, 17 December 2019

Root Cause Report, Inadequate Response to Unplanned Environmental Tritium Releases from Braidwood Station Due to Weak Management Oversight and the Lack of Integrated Procedural Guidance
ML102600357
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Issue date: 11/30/2005
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6-,,e,ýOA liýýO+ eAU44-1 ROOT CAUSE REPORT TITLE: Inadequate response to unplanned environmental tritium releases from Braidwood Station due to weak managerial oversight and the lack of integrated procedural guidance.

Unit(s): Braidwood Units 1 and 2 Event Date: 11/30/2005 Event Time: 11:50 Action Tracking Item Number: 428868 Report Date: 02/14/06 Sponsoring Manager: I Janice Kuczynski Investigators: Position "Jason Eggart /

Braidwood Chemistry Lead Investigator

'Tom Leffler Root Cause (RC) Qualified Investigator Randy Kalb Dresden Chemistry Investigator Kim Aleshire Braidwood EP (ODCM) Investigator Glen Vickers LaSalle RP Investigator Scott Kirkland Quad Cities Investigator Jim Crawford I BWD CMO RC Qualified Investigator Mike Miller Braidwood Operations Jeff Burkett Braidwood Operations Dan Stroh Braidwood Engineering Carl Dunn Senior Mentor Executive Summary:

Reason for Investigation:

Braidwood Station identified low levels of elevated tritium in the groundwater on and in the vicinity of Braidwood Station property (See Attachment 7 for Map). The presence of these elevated levels exceeds levels specified in Illinois EPA regulations (Attachment 10). The Illinois Environmental Protection Agency (IEPA) groundwater limit for tritium concentration parallels the Federal EPA regulation for annual radiation limits due to drinking water radioactivity. The statutes imply that four (4) mrem would not be exceeded if less than two liters of water at the IEPA limit were.:.

ingested daily for a year. In addition, the U.S. Nuclear Regulatory Commission (NRC) provides limnits on liquid effluent releases and how those effluents must be

monitored and reported. The NRC has reached a preliminary conclusion that Braidwood may not have satisfied all associated regulations in this regard. When the inspection exit for the current NRC review is completed, any potential violations will be entered into the Braidwood Corrective Action Process. This report provides insights on the causes of these potential violations and associated corrective actions. Additional investigation will be performed commensurate with the content of any such potential violations.

Scope of the Review:

The first focus of this root cause investigation is to determine the root cause(s) of and appropriate corrective actions for the unplanned tritium releases from Braidwood Station (See Attachment 1). The Braidwood Tritium Remediation Team has responsibility under Action Request (AR) 435383 for corrective actions to prevent future unplanned tritium releases to the environment and to remediate the existing condition of detectable tritium in groundwater on and in the vicinity of Braidwood Station property. The second focus of this root cause team is to evaluate the effectiveness of Braidwood's response to the Circulating Water (CW) Blowdown (BID) leaks, which deposited tritiated water on the ground during 1998 and 2000 as well as during the smaller volume leaks, which both preceded and succeeded the 1998 and 2000 leaks. If this investigation determines that Braidwood's response actions were not effective, this root cause team will determine the root cause(s) and appropriate corrective actions for those ineffective response actions.

Root Causes and Corrective Actions to Prevent Recurrence (CAPRs):

The root cause of the large volume leaks in 1998 and 2000 is documented in Root Cause Report (RCR) 38237, which determined that the Circulating Water (CW)

Blowdown (B/D) Vacuum Breaker (VB) Valves had inadequate preventative maintenance programs and inadequate design configuration (Root Cause 1). The Corrective Actions to Prevent Recurrence (CAPRs) from RCR 38237 were to institute a Preventative Maintenance Program and system modifications, which are complete and have been verified to be effective in preventing major vacuum breaker valve failures that resulted in large volume spills (CAPR 1). The root cause of the small tritiated water leaks, which both preceded and succeeded the 1998 and 2000 leaks, was that the need for a near zero leakage standard was not identified due to a then-existing lack of Technical Rigor/Questioning Attitude (Root Cause 2). The Braidwood Tritium Remediation Team will determine the methodology and implement the plan for future radiological releases, including leakage standards under IR 435383 and effectiveness review ATI# 428868 (CAPR 2). HU-AA-102 and HU-AA-1212, Technical Human Performance Practices and Technical Task Risk/Rigor Assessment, Pre-Job Brief, Independent Third Party Review, and Post-Job Brief procedures have been instituted to improve technical rigor, questioning attitude, and attention to detail (CAPR 3).

2

This Root Cause Team determined that Braidwood's response to the 1998 and 2000 events was ineffective. The response to the 1998 and 2000 releases of radioactivity (tritium) to an unplanned location is indicative of ineffective corrective actions. As directed by the root cause charter (Attachment 1), these ineffective corrective actions are addressed in this root cause report.

The first root cause for the ineffective response was a lack of integrated procedural guidance to ensure proper recognition, evaluation, and timely mitigation of the radiological spill events (Root Cause 3). Integrated procedures will be developed and implemented to provide detailed spill and leak response requirements which will ensure full compliance with 3

State and Federal laws and regulations and to integrate Exelon resources to respond to radiological leaks and spills (CAPR 4). A second root cause for the ineffective response was weak management review and oversight of spill response activities (Root Cause 4).

Specifically, management had a weak questioning attitude and an inadequate challenge culture regarding the 17 CW B/D leaks over the 10 year period bridging 1996 to 2006. Exelon Corporate, the Issues Management Team, and Braidwood Senior Management did not track characterization and mitigation plans to completion during and following the year 2000 spill. HU-AA-102 and HU-AA-1212, Technical Human Performance Practices and Technical Task Risk/Rigor Assessment, Pre-Job Brief, Independent Third Party Review, and Post-Job Brief procedures have been instituted to improve technical rigor, questioning attitude, and attention to detail (CAPR 3).

OP-AA-106-101-1002, Exelon Nuclear Issues Management, will be revised to: 1) improve Corrective Action Program (CAP) controls of Issues Management teams, 2) utilize the tools and techniques of the Exelon HU-AA-102 and HU-AA-1212, Technical Human Performance Practices and Technical Task Risk/Rigor Assessment, Pre-Job Brief, Independent Third Party Review, and Post-Job Brief procedures, 3) strengthen reporting requirements to station Senior Management, and 4) define station Senior Management responsibilities for oversight and challenge of events and issues from initial identification to final disposition (CAPR 5).

Extent of Condition:

Exelon Nuclear is evaluating the potential for unplanned tritium releases at each of its facilities, with added emphasis on Pressurized Water Reactors due to tritium production rates. Nuclear Event Report (NER 428868-12) will require all Exelon Sites to take actions to research historical spills and determine if tritium remediation is required. The nuclear industry will be informed of the issue through a Nuclear Network Operating Experience Report (NNOE 428868-13). Other spill type (Hazardous Material) response procedures were reviewed and determined to have effective guidance through the Hazmat and Environmental programs (Attachments 2

& 8). These programs and procedures will receive further review and update to integrate radiological interfaces (CAPR 3).

4

Risk Assessment/ Reportability:

The Nuclear Safety Risk Assessment showed no impact on station operation or response to postulated accident conditions. The event was reportable under Reportability Manual, SAF 1.9, News Release or Notification of Other Government Agencies per 10 CFR 50.73.

Previous Events:

Since 1996, 17 CW B/D valve leaks were noted in the Braidwood Corrective Action Database and Work Control System as documented in Table 1 of this report in the Events Description Section. Responses varied from a request for a normally scheduled repair to immediate remediation efforts. The best response, which occurred in year 2000, removed water from the spill area, but did not effectively determine the extent of condition for full remediation.

Condition Statement:

In response to an Illinois Environmental Protection Agency (IEPA) inquiry in March 2005, Braidwood Station began taking a series of groundwater samples within Braidwood Station property boundaries. Some of those samples identified elevated levels of tritium in the Braidwood Station groundwater. Issue Report (IR) # 328451 documented these monitoring results in April 2005. This sampling continued over a period of eight months.

In response to the results of these initial and follow-up monitoring samples, an Issues Management Team was formed on November 30, 2005 in accordance with Exelon procedure OP-AA-106-101-1002. Additional sampling resulted in elevated tritium levels being identified in groundwater in the vicinity of Circulating Water (CW)

Blowdown (B/D) system Vacuum Breakers (VB) #2 and CW B/D VB #3, which had experienced large volume leaks in 1998 [(VB 3) Problem Identification Form (PIF) #

Al 998-04324] and in 2000 [(VB 2) IR # 38237].

On 30 November 2005, the Issues Management Team (IMT) initiated IR# 428868 reporting that elevated levels of tritium had been detected in onsite groundwater sampling wells and triggering this root cause investigation and report. Subsequent sampling identified elevated tritium levels outside Braidwood Station property boundaries.

On 16 December 2005, the Illinois Environmental Protection Agency (IEPA) issued Violation Notice W-2005-00537 to Exelon Generation - Braidwood Station, alleging Impairment of Resource Groundwater.

See Attachment 6 for an overview of the Circulating Water (CW) Blowdown (B/D)

System operation. See Attachment 7 for a map of the affected areas.

5

Event

Description:

Braidwood Station identified elevated levels of tritium in the groundwater that exceed Illinois EPA regulations (Attachment 10). Due to the extended period of time and the number of events covered in this root cause investigation, the timeline became very complex. For clarity, the Event Description has been organized as follows:

The Events and Causal Factors (E&CF) Chart has been placed in Attachment 4.

Page 1 of 3 of the E & CF chart depicts the timeline for all vacuum breaker issues.

Page 2 of 3 and page 3 of 3 depict barrier analysis of the events on VB-2 and VB-3.

Displayed in this event description section are:

a. Table 1, Circulating Water (CW) Blowdown (B/D) Leak Table, which details the leaks that have been identified during this investigation.
b. Event timeline summary with events that led up to this Root Cause Investigation.
1. Attachment 12, CW B/D VB-2 and VB-3 detailed timelines.
a. Leaks that are within the scope of this investiqation The elevated levels of tritium have been determined to have originated from historical spills from the CW B/D system. Since 1996, 17 CW B/D vacuum breaker leaks were noted in the Braidwood Corrective Action Database and work control database. The following table is a summary of leaks identified from records, including the station's response.

This team did not locate any computerized records of the Work Orders or Problem Identification Forms (PIFs) prior to approximately 1996. As such, the quantification of and response to these events had to be recreated from historical documents and interviews of involved personnel. Two means of identifying the impact of potential leaks from initial plant operation in 1988 to 1996 were considered. The first was to pull microfiche records for review and the second was to perform direct characterization of the conditions in the vicinity of all of the Circulating Water (CW)

Blowdown (B/D) Vacuum Breakers (VBs).

Because of the need to have full confidence in the characterization of conditions in the vicinity of the vacuum breakers, the decision was made to install both deep and shallow monitoring wells in the vicinity of all of the CW B/D vacuum breakers. This was determined to be preferable to depending on locating microfiche records for possible leaks and monitoring only those locations.

6

Table 1: CW BID Leak Table

RESPONSE

PIF/ Immediate Particulate Tritium 10 CFR

  1. Date Event Leak Size WR CRAIR Action Sample Sample 50.75(g) Resolution l 11/27/96 VB-1 -250,000 WO, 'rocess had Requested No 1996 No 1996 No 1996 06/19/97 1" pipe to air leak gals 96111970 personnel repair., documents documents documents release valve broke.

decide found. found. found. Tritium plume was WR or Will be Tritium Will be identified around VB-I PIP. So,Reeito oPIF, WR addressed plume was addressed in 2006. Remediation only. under ATI# identified in under ATI# being addressed under 435383 2006. Will 435383 IR# 435383.

be addressed under ATI#

_435383 2 1/5/98 VB-2 leak Small leak. WR# 1rocess had Requested No 1998 No 1998 No 1998 11/08/00 replaced the 98000682 personnel repair documents documents documents float, replaced vacuum decide found. found. found. breaker and isolation WR or Will be Tritium Will be valve. Tritium plume PIF. So, addressed plume was addressed was identified around o l WR under ATI# identified in under ATI# VB-2 in 2005.

only. 435383 2005. Will 435383 Remediation being be addressed addressed under IR#

under ATI# 435383.

435383 3 12/4/98 VB-3 Caused WO A1998- Isolated 04/26/01 No 1998 07/25/01 05/20/02 1" pipe to the leak - seat flooding. - 98127749 04324 air release Soil documents evaluation air release valve broke 3M gals valve until Particulate found. detected due to corrosion. Guide

  • parts radioactivity Tritium particulate post sheared weld off could be above plume was radioactivity, float. Entire vacuum received, background. identified in breaker replaced (July This 2005. Will 2001). Tritium plume stopped be addressed was identified around this under ATI# VB-3 in 2005.

leakage. 435383 Remediation being addressed under IR#

_435383.

4 11/6/00 VB-2 Caused WO A2000- Replaced Particulate Tritium Yes. 11/06/00 Float broke on leak- flooding. - 98003276 04281 vacuum radioactivity plume was Sampling vacuum breaker. Tritium seat 3M gals Root breaker above identified detected plume was identified Cause background. around VB-2 particulate around VB-2 in 2005.

38237 in 2005. radioactivity. Remediation being Will be addressed under IR#

addressed 435383.

under ATI#

435383 5 11/10/00 VB-6 Small leak WO None. Requested No 2000 No 2000 No 2000 10/17/05 Valve leak 99231846 IR should repair. documents documents documents assembly replaced. 2006 have been found. found, found. remediation sampling seat written. Will be 2006 Will be showed no tritium in the addressed samples addressed groundwater at this under ATI# show no under ATI# location.

435383 tritium in the 435383 groundwater_

7

RESPONSE

PIF/ Immediate Particulate Tritium 10 CFR -

  1. Date Event Leak Size WR CR/IR Action Sample Sample 50.75(g) Resolution 6 11/20/00 VB-1 Vacuum WO None. Rebuilt 11/20/00 Tritium Yes. 11/21/00 Rebuilt valve leak breaker 99233404 IR valve, samples sampling Sampling internals. Tritium lifting. should reported was reported plume was identified have negative for performed negative for around VB-1 in 2006.

been detectable no detectable detectable Remediation being written. radioactivity, activity. radioactivity addressed under IR#

1_ 435383.

7 6/18/01 VB-3 1/2 GPH leak WO 4,2001- Sampled No 2001 Tritium No 2001 05/20/02 Rebuilt leak from main 98127749 01806 water, documents plume was documents valve. Tritium plume vacuum found. identified found. was identified around breaker. Will be around VB-3 Will be VB-3 in 2005.

addressed in 2005. Will addressed Remediation being under ATI# be addressed under ATI# addressed under IR#

435383 under ATI# 435383 435383.

435383.

8 6/18/01 VB-9 Water in N/A A2001- Sampled Negative for No 2001 No 2001 No active leak.

vault. 01806 water, detectable documents documents Attributed to particulate found. No found. groundwater, 2006 adioactivity. tritium in 2006 remediation sampling groundwater remediation showed no tritium in at this sampling the groundwater at this location showed no location.

reported in tritium.

2006.

9 6/18/01 VB-10 Water in N/A A2001- Sampled Negative for No 2001 No 2001 No active leak.

vault 01806 water, detectable documents documents Attributed to particulate found. No found, groundwater. 2006 radioactivity. tritium in Will be remediation sampling groundwater addressed showed no tritium in at this under ATI# the groundwater at this location in 435383 location.

2006.

10 6/18/01 VB-11 Water in N/A A2001- Sampled No 2001 No 2001 No 2001 No active leak.

vault 01806 water. documents documents documents Attributed to found, found. No found. groundwater. 2006 Will be tritium in Will be remediation sampling addressed groundwater addressed showed no tritium in under ATI# in 2006. under ATI# the groundwater at this 435383 435383 location.

11 5/4/02 VB-3 Seepage WO 106767 Requested Sample Per IR, RP No 2002 05/20/02 replaced air leak - vent 0440231 repair. showed was documents elease valve. Tritium above sampling. No found. plume was identified background documents Will be round VB-3 in 2005.

particulate found. Will addressed Remediation being activity. Will be addressed under ATI# addressed under IR#

be addressed under ATI# 435383 435383.

under ATI# 435383 435383 8

RESPONSE

PIF/ Immediate Particulate Tritium 10 CFR

  1. Date Event Leak Size WR CRJIR Action Sample Sample 50.75(g) Resolution 12 8/20/03 VB-4 1 gpm to WO 172376 None Sample No 2003 No 2003 9-9-03 replaced seat seat vault, no 99243232 analysis documents documents ring/float and top flooding detected no found. found, gasket.

particulate Tritium Willbe radioactivity plume was addressed 8/27/03 173204 Stopped identified in under ATI# Tritium plume was mod 2006. Will 43538310. identified around VB-testing. be addressed 4 in 2006.

under ATI# Remediation being 435383 addressed under IR#

435383.

13 9/11/03 VB-4 20-40 WO 175241 Secured No 2003 No 2003 No 2003 10/22/03 No work seat drops/min 99243232 booster documents documents documents performed. Leak pumps. found. found. found. determined to be from Will be Tritium Will be operating the system at addressed plume was addressed low flow. Tritium under ATI# identified in under ATI# plume was identified 435383 2006. Will 435383 around VB-4 in 2006.

be addressed Remediation being under ATI# addressed under IR#

435383 435383.

14 11/18/04 VB-8 Popping / WO 274328 Isolated No 2004 No 2004 No 2004 10/18/05 replaced leaking, 0757898 Vacuum documents documents documents valve assembly. 2006 small leak breaker found. found. found. remediation sampling within pit showed no tritium in the groundwater at this location.

15 5/19/05 VB-I 20 drop per WO 336401 Isolated No 2005 Yes. Will be 12/18/05 replaced the minute leak )0744194 valve and documents Sampling addressed vacuum breaker from the air and WR requested found, was under ATI# assembly. Tritium release D0178930 repair. performed. 435383 plume was identified valve. Tritium around VB- I in 2006.

plume was Being addressed under identified in IR# 435383.

2006. Will be addressed under ATI#

435383 16 5/24/05 VB-6 Seepage WO 338111 Isolated No 2005 Per IR, Will be 10/19/05 rebuilt main seat from float/ 00820879 leaking documents sampling addressed valve and replaced air seat area vacuum found, was under ATI# release valve. 2006 with one breaker. performed. 435383 remediation sampling foot of water showed no tritium in in pit. the groundwater at this l6cation.

9

RESPONSE

PIF/ Inunediate Particulate Tritium 10 CFR

  1. Date Event Leak Size WR CR/IR Action Sample Sample 50.75(g) Resolution 17 1/16/06 VB-7 Bushing WO 442540 Reduce Sample No Will be Pending EACE in failure. Not 0883925 B/D. Take analysis detectable addressed progress. Tritium plume significant.. samples. detected no tritium in under was identified around Evaluated particulate surface water ATI# VB-7 in 2006, but was for radioactivity from this 435383 due to historical regulatory leak. Prior to leakage. Remediation complianc this leak, being addressed under e, isolated tritium above IR# 435383.

valve and background wrote WR & below EPA drinking water limit identified in 2006 in wells used to characterize conditions near this vacuum breaker.

Responses varied from a request for normally scheduled repairs to an immediate remediation effort. The 2000 response effectively remediated the surface spill area, but did not effectively characterize the extent of condition to allow for full remediation due to weak management review and oversight of spill response activities (Root Cause 4). A contributing cause common to many of the documented events is the lack of questioning attitude and oversight by Braidwood Senior Management to the radiological implications of blowdown spills. Issue ownership and follow through were lacking in all levels of management. Corrective actions 2 and 3 address training for all levels of management.

The tritium remediation plan will be tracked to completion under IR# 435383 and CAPR 2. The Braidwood Tritium Remediation Team has performed tritium characterization for the Circulating Water (CW) Blowdown (B/D) Vacuum Breakers (VBs) and performed integrity tests of the blowdown line. As of January 31, 2006, CW B/D piping acoustic testing determined that no leak above 1.0 gpm existed (minimum detectable level of testing equipment). The characterization of tritium levels in the vicinity of the vacuum breakers is described in Table 1. The station secured radioactive releases to the blowdown line on 11/23/05 and releases will remain secured until the tritium remediation team issues the final resolution under ATI# 435383-07.

10

b. Event timeline with events that led up to this Root Cause Investigation October 1990 "DRAFT" Commonwealth Edison procedure, CSG-001, "General Action Plan for Response to Unmonitored Releases and Very Low Level Radioactive Spills" was developed in 1990 but not implemented. This procedure contained guidance for mitigating intrusion of low-level radioactive spills into the groundwater. The reason the procedure was not implemented could not be identified. The failure to implement this procedure was not determined to be a root cause for three reasons. First, this procedure did not provide overall integrated guidance for spill evaluation and mitigation. Second, the reason the procedure was not implemented could not be identified. Third, no corrective action to prevent recurrence could be determined. Therefore, the lack of integrated procedural guidance to ensure proper recognition, evaluation and timely mitigation of the radiological spill events was considered a root cause (Root Cause 3) for the ineffective response to Circulating Water (CW)

Blowdown (B/D) Vacuum Breaker (VB) leaks (Causal Factor 3, Root Cause 3).

1991

  • Illinois regulation 35 IAC 620 enacted, which places radioactivity limits on potable resource groundwater tritium concentration. This new regulation was not integrated into Company Procedures (CausalFactor6).

November 26, 1996

  • Found 1" pipe from VB-1 to the air release valve failed. Estimated 250,000 gallons released to the ground.

In 1996, VB-1 had a leak of approximately 250,000 gallons due to an air release valve failure. The only documented response to this event was a work order (96111970) to isolate and repair the valve. The work control process (currently Exelon procedure WC-AA-106) had no guidance for prioritizing radiological leaks which could enter the groundwater. (Failed Barrier 5). In the absence of any other recognized hazard, the current process prioritizes these work orders as a "C".

Corrective action 26 will revise WC-AA-106. No documentation could be found to indicate that any actions were taken to remediate the spill or address the potential radiological concerns. Since there was no Problem Identification Form (PIF) written to document the failure, there is no record of review of this event by Braidwood Senior Management. During this team's review of this event, the team could not find any documentation of sample analysis for radioactivity.

11

Station actions and interviews of site personnel documented that in the past, personnel did not respond to CW B/D leaks as an offsite radioactive release.

Rather, they focused on preventing. potential National Pollution Discharge Elimination System (NPDES) violations. As long as the effluent (water) did not leave Exelon property, personnel did not always perceive a reason for concern, as NPDES requirements were considered met. The site personnel interviewed, that were present at the time of the 1996 event, were unaware of the Illinois regulation regarding groundwater tritium limits. Engineering walkdown Preventative Maintenance (PM) procedure (currently Exelon Braidwood procedure ER-BR-400-101) and Operations Department (OPS) walk down PM procedure (currently Braidwood procedure OBwOS CBW-A1) did not contain any precautions or steps for addressing CW B/D spills that potentially contain tritium (Failed Barriers 12 & 13).

Operational procedures BwOP CW-12, BwOP WX-526TI and BwOP WX-501TI had no guidance to isolate the B/D system if a known leak had occurred during a routine radiological release to the Kankakee River (Failed Barriers 15, 16, & 17).

No documentation was located that implied a recognition of vacuum breaker leakage impact on the requirements of the ODCM, REMP (Radiological Effluent Monitoring Program), and 10CFR50.75(g). The 1996 Annual Effluent Report did not contain an evaluation of the vacuum breaker radioactivity released and did not contain the associated evaluation of the dose to the public (IR 455079) & (CA-15).

NOTE:

As of January 2006, Elevated levels of tritium have been identified in the groundwater on Braidwood Station property close to VB-I. In one location on Braidwood property, the level of tritium was above the Illinois EPA ground water standards (20,000 picoCuries/liter). At Braidwood Station there was no site or corporate procedure for guidance on low-level radioactive spills (Failed Barriers 4 & 6). The Hazmat procedures (BwAP 750-4 & BwAP 1100-16) did not address radiological spills (Failed Barriers 1 & 2).

December, 1998

  • Leak from VB-3. (See Attachment 12 for more details.)

November 20, 2000

  • Leak from VB-1.

12

November, 2000

  • Leak from VB-2. (See Attachment 12 for more details.)

December 2000

  • VB-2 Root Cause Report 38237 for equipment failures was completed.

December, 2004 Based on Operating Experience from the nuclear industry (OPEX),

Braidwood Station commenced increased investigation of environmental tritium.

January, 2005 Exelon chartered an investigation into tritium OPEX issues, with Braidwood Station providing a multi-disciplined team to support the efforts to better understand and mitigate environmental tritium issues.

March 17, 2005

  • On March 17th, the Illinois Environmental Protection Agency (IEPA) notified Exelon Nuclear Corporate Environmental that they were investigating tritium concentrations in wells near Braidwood Station in preparation for the Godley public hearing on Braidwood Station's NPDES permit renewal. [The Root Cause Team could not find evidence of entry of this item into the Corrective Actions Program (Missed Opportunity)].

" The IEPA was working with Exelon Nuclear Corporate Environmental to understand why one of the Braidwood Radiological Effluent Monitoring Program (REMP) wells along the Kankakee River was indicating about 400 pCi/L concentration of tritium. [Since initial REMP sampling was commenced, the Braidwood REMP reports documented two wells along the Kankakee River with elevated tritium (within limits). One well returned to background levels when the well was redrilled (new casing)]

" The IEPA was investigating why shallow groundwater well #2 in Godley was reported to have tritium. (Exelon Corporate Environmental log documents that Exelon, an independent contractor, and the IEPA analyses could not confirm any tritium above background levels in any of the Godley, IL wells.)

13

March 23, 2005 The Exelon Corporate Environmental log documents that Exelon, an independent contractor, and the IEPA analyses of samples from wells in Godley Illinois did not detect any tritium above background levels.

In preparation for the upcoming public meetings for the city of Godley, the IEPA requested (by phone) Exelon Corporate Environmental to have Braidwood Station sample for tritium at the following locations:

1. The cooling lake discharge canal
2. The northwest corner of the cooling lake
3. The two monitoring wells used for the previous environmental remediation sampling on the west side of the Turbine Building.

" The IEPA was informed that Exelon installed wells to determine a groundwater gradient near the blowdown line spill at VB-2 that occurred in November 2000. These wells were installed for hydrology analysis.

  • The IEPA requested that Exelon provide a sample of the offsite drainage ditch and samples from the four shallow monitoring wells that were installed in the area of the November, 2000 blowdown line leak.
  • The IEPA asked Braidwood Station to sample the shallow Godley well, which was reported to be contaminated with tritium, because the Agency would like to have a recent tritium analysis on it.

March 24, 2005 An Independent contractor sampled the following per IEPA March 23, 2005 request:

1. The cooling lake in the discharge canal
2. The cooling lake in the northwest corner
3. The two monitoring wells used for the previous environmental remediation sampling (two wells closest to the Turbine Building)

Additional Exelon samples:

4. The cooling lake on the east-west dike approximately halfway in the middle
5. The offsite drainage ditch
6. The four shallow monitoring wells that were installed in the area of the November 2000 blowdown line leak 14

April 1, 2005 Results (reference Braidwood Chemistry Department Sample Log) from the March 24 tritium samples taken at Braidwood Station indicated presence of tritium above background in the following locations (See Attachment 7 for Map):

1. The cooling lake in the discharge canal - < background
2. The cooling lake in the northwest corner - < background
3. Sample point MW-4, near the November 2000 VB-2 leak -. above background Sample point MW-6, West side of Turbine Building - above background Additional Exelon samples
4. The cooling lake on the east-west dike approximately halfway in the middle - < background
5. Sample point BD-101, Braidwood drainage ditch - above background
6. The four shallow monitoring wells that were installed in the area of the November 2000 blowdown line leak. Three were < background.

One was above background The levels identified in these samples were well below the federal standard of 20,000 picoCuries/liter (pCi/L).

  • Although the tritium levels were well below federal standards, Braidwood commenced detailed sampling and investigation.

April 15, 2005 Exelon sent Godley well results and the second sample on the drainage ditch to the IEPA. Samples had been collected on April 7, 2005:

Sample Location Sample ID Result BD-101 (Drainage Ditch) BDSW-1 665 twice background Godley Rec. Center BDWW-1666 less than background Godley Rec. Center BDWW-1 667 less than background April 25, 2005 IR 328451 was generated to identify tritium levels above background in the Braidwood drainage ditch.

15

May 5, 2005

  • Additional samples were taken at three locations in and around the Braidwood drainage ditch in an attempt to better define the source of the tritium.

May 9, 2005

  • Due to the results of the March 24, 2005 sample and confirmatory sampling of Braidwood drainage ditch, Braidwood Station expanded the sampling and investigation to focus on both surface water and groundwater sample points.

May 10, 2005 Five shallow groundwater wells (GW-1, GW-2, TW-20, OW-32 and OW-

33) were sampled (See Attachment 7 for Map). These five wells are located onsite and are positioned between the Braidwood drainage ditch and the Village of Godley. These samples were to provide more detailed information to samples previously collected on May 5. No tritium was detected above background concentrations in any of these five samples.

May 17, 2005

" A conference call was held with IEPA to exchange recent sample results and to discuss sampling in the Braidwood Station onsite wells (GW-1, GW-2, TW-20, OW-32 and OW-33) (See Attachment 7 for Map). The IEPA reported all tritium samples as less than background, which corroborated the site's results.

" The IEPA stated that they would acquire four samples from residents in Godley who live along side the drainage ditch and would analyze the samples for tritium. The Agency would provide duplicate samples for Exelon tritium analyses and would notify us when the sampling was scheduled.

May 18, 2005 A 20 drop per minute leak from the pilot valve of vacuum breaker #1 (VB-

1) was identified during a walk down by Braidwood Engineering. A sample was acquired and sent for analysis. (See Attachment 7 for Map) 16

May 19, 2005 The tritium concentration in the sample of the leak catch tray at the VB-1 leak was above the IEPA standard for groundwater. (There was no evidence of leakage outside of the catch tray).

May 23, 2005

" Braidwood Station briefed the Nuclear Regulatory Commission (NRC)

Inspector from the Region III Office on the drainage ditch tritium results.

An overview of the sampling performed to date, along with the results of the sampling and a copy of the collated sample results, were presented to the NRC as part of the routine Offsite Dose Calculation Manual (ODCM)/Radiological Environmental Monitoring Program (REMP) inspection.

  • Tritium analyses performed on five water samples collected at Braidwood Station on May 20, 2005 were less than background except for the VB-3 Pit tritium concentration which was above background (See Attachment 12 for VB-3 timeline).

June 14, 2005

  • Exelon and IEPA acquired four samples from the Godley wells per the May 17 request.

June 20, 2005

  • As part of the investigation to determine the source of tritium, the station received the independent contractor proposal to install monitoring wells to focus on:

o Examining the groundwater impact in the area of VB-1 located south of the switchyard o Determining the movement and direction of groundwater and its relationship to surface water on both the east and north side of the Braidwood Station property June 28, 2005

  • The results of the four Godley well samples taken on June 14, showed no tritium levels above background.

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July 22, 2005 Exelon installed monitoring wells to investigate potential leakage around VB-1 and VB-3 that may be contributing to leakage in the Braidwood drainage ditch: (See Attachment 7 for Map) o Sample point MW-1 06, near the fresh water holding-pond o Sample point MW-1 07, SE corner of the switchyard near VB-1 o Sample point MW-108, east of VB-1 near the CW B/D line o Sample point MW-1 09, east of the switchyard near the Braidwood ditch September 23, 2005 Exelon pursued additional resources to expand the scope of the tritium investigative activities to more clearly define the source of the tritium, which had been discovered in the drainage ditch. This information was communicated by phone to the IEPA.

October 2005

  • Exelon installed monitoring wells as part of an expanded scope of the tritium investigation: (See Attachment 7 for Map) o Sample point MW-110, north of the meteorological tower o Sample points MW-111, MW-112, and MW-113, north property line near Smiley Road October 25, 2005 Initiated IR# 390133 to address difference between historical annual liquid discharge curie content and the UFSAR description. Investigation of this difference determined that no change was required.

November 9, 2005 Two of the four groundwater samples collected on October 19 and October 20, 2005 from the new monitoring wells exceeded the Offsite Dose Calculation Manual (ODCM) Lower Limit of Detection of 2000 pCi/L.

Upon this indication, Braidwood Station assembled an Exelon Issues Management Team (OP-AA-1 06-101-1002) to evaluate the tritium issue.

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November 22, 2005 Nuclear Oversight (NOS) completed the ODCM, REMP, Effluent and Environmental Monitoring Audit Report, NOSA-BRW-05-08 (AR# 287718).

NOS found no issues of note. NOS did not identify that the ODCM did not include Illinois State Groundwater Regulations (Failed Barriers 28 & 29).

November 23, 2005

  • Braidwood Station terminated the use of the Circulating Water (CW)

Blowdown (B/D) system for radioactive liquid releases pending resolution of this root cause investigation and appropriate corrective actions.

November 30, 2005

  • Issues Management Team was formed to address tritium issues.

December 2, 2005

  • Emergency Notification System (ENS) notification made to the NRC due to the notification of other -government agencies' (IEPA) and a press release.

January 15, 2006 As this RCR was being finalized, a leak occurred on VB-7 due to failure of an internal guide and was documented on IR# 00442540. (See analysis section of how this issue is addressed) (See Attachment 7 for Map)

  • The standing water posed no radiological concern because CW B/D radiological releases had been held in abeyance since November 23, 2005.
  • The standing water in the vicinity of VB-7 was sampled for gamma radioactivity and tritium (no radioactivity detected) and evaluated for NPDES compliance. An environmental specialist verified that the leakage did not reach runoff ditches or creeks and therefore NPDES requirements were met.
  • Prior to this leak, tritium above background and below the EPA drinking water limit was identified in 2006 in wells used to characterize conditions near this vacuum breaker. The source of this tritium is likely to be leakage prior to 1996 as no record of leakage subsequent to 1996 could be located.

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Analysis:

The Root Cause Investigation Team interviewed personnel and reviewed the response procedures, regulations, historical documentation, and environmental impacts. An Event and Causal Factor (E&CF) Chart (Attachment 4) was utilized for Cause and Effect Analysis (Attachment 3), Change Analysis (Attachment 5) and Barrier Analysis (Attachment 2).

Unplanned Tritium releases from Braidwood Station:

The 2000 event Root Cause Report (RCR) 38237 CAPR's addressing the vacuum breaker failures were reviewed and have been determined effective in preventing major vacuum breaker failures since 2000 through the end of 2005. The purpose of the Root Cause in 2000 was to determine the cause of those failures. RCR 38237 CAPR implemented a revised preventive maintenance program for the float operated vacuum breaker valve assemblies for the CW B/D and Makeup Systems.

This Preventative Maintenance (PM) was developed to include specific intervals for inspection of valve internals and provided for periodic replacement of the valves (refer to Attachment 6 for CW B/D description). This team concludes that the RCR 38237 CAPRs have effectively prevented recurrence of the large volume leaks (as described in Table 1) caused by corroding valves that did not receive effective PMs and water hammer damage due to design configuration. Currently, daily walkdowns of the blowdown vacuum breakers are being performed to verify that no leakage is occurring.

On January 16, 2006, a leak occurred on VB-7 due to failure of an internal guide bushing and was documented on IR 00442540. EACE 442540 is performing an evaluation of this failure. The results of the EACE will be reviewed to determine if the findings in this root cause are still valid. Corrective Action 29 will track this issue. The standing water posed no radiological concern because radiological releases through the CW B/D line had been terminated pending completion of this root cause report and completion of associated corrective actions.

Root Cause Report (RCR) 38237 Corrective Action to Prevent Recurrence (CAPR) revised the system walkdown inspection requirements, including specified frequency of walkdowns and documentation and reporting of walkdown results. RCR 38237 CAPR also replaced the vacuum breaker assembly with a surge-protected configuration.

Engineering has performed an effectiveness review of these actions (ATI 38237-10) and in the three years since the initial effectiveness review, there had been no major equipment failures, which leads to the conclusion -that the actions taken from the root cause report are effective in eliminating the possibility of large volume leakage due to major vacuum breaker failure.

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Effectiveness of Braidwood Station response to radioactive leaks:

Interviews played an integral part in the determination of this root cause due to the lack of written information that was available from the Corrective Action Program (CAP) to this Root Cause Investigation Team for the Circulating Water (CW)

Blowdown (B/D) events. The fact that some spills were not captured in the Corrective Action Program is indicative of weak management review and oversight of spill response activities (Root Cause 4).

A potential root cause that was considered was that draft Commonwealth Edison procedure CSG-001, "General Action Plan For Response To Unmonitored Releases And Very Low Level Radioactivity Spills" was not implemented. This procedure contained guidance for mitigating intrusion of low-level radioactive spills into the groundwater. There was no reason found as to why the procedure was not implemented.

The failure to implement this procedure was not determined to be a root cause for three reasons. First, this procedure did not provide overall integrated guidance for spill evaluation and mitigation. Second, the reason the procedure was not implemented could not be identified. Third, no corrective action to prevent recurrence could be determined. Therefore, the lack of integrated procedural guidance to ensure proper recognition, evaluation and timely mitigation of the radiological spill events was considered a root cause (Root Cause 3) for the ineffective response to Circulating Water (CW) Blowdown (B/D) Vacuum Breaker (VB) leaks (CausalFactor3, Root Cause 3).

For example, in a number of events the station addressed the NPDES concerns but no Radiation Protection (RP) individuals were engaged to address radiological concerns. Additionally, when personnel with the requisite knowledge base were involved, the lack of a pre-engineered solution that could be executed was not available. This hampered response, as each step had to be created and reviewed before actions occurred. At the time of the 2000 spill, the final remediation steps were missed under these circumstances, as independent expert reviews/challenges did not occur.

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Evaluation Methods used during the investigation process for the Root Cause.

RC Tool Why used Advantages Disadvantages overcome Event and Causal Utilized due to the complexity Provide an illustration of the While time consuming, enlisted Factor Chart (Att 4) of the issues and actions over whole problem and a full-time Root Cause person time. contributing factors, for the skill/experience and Works very well with barrier time large The to create an E&CF number Chart.

of events verge n a ever, analysis, which became necessary during the verged on a CCA. However, evaluation, one event was taken to represent them all and the analyses were completed utilizing that event (the 1998 event) as the template.

TapRoot Used to assign the cause codes Consistent approach for more Difficult to utilize and for individual causes of the reliable cause coding. understand categories.

event. Technique was used in conjunction with Trending/Coding procedure and Team input/brainstorming of causes.

Barrier Analysis (Att 2) Used extensively, as people, Used to identify causal factors Utilized Team brainstorming to physical, and administrative systematically, With the E&CF assure all barriers were barriers should have prevented chart and Cause & Effect recognized.

the issue. analysis to identify process weaknesses. Supports proposed corrective actions.

Change Analysis Team tried to utilize to evaluate Made for a good starting point Information contained in this (Att 5) changes in procedures and in analysis of the E&CF chart, attachment was inadequate to regulations. use effectively and was therefore not utilized as an input to this root cause report.

Cause and Effect Found the "Why" Stair Case This analysis method was key Utilized E&CF chart and area Analysis (Att 3) instrumental due to the large in finding the common/root experts in OPS, RP, Chemistry number of failed barriers, cause used with barrier - Environmental, and other analysis. stations as well as RA and Corporate to ensure entire background was understood for this complex problem.

Failure Modes and Not Used Not Used Not Used Effects Analysis 22

Evaluation:

Cause (describe the cause and Po m identify whether it Problemis a root cause or a Statement contributing cause) Basis for Cause Determination Unplanned Causal Factor 1,

  • Preventive Maintenance -The preventive maintenance program in year 2000 releases to the Root Cause 1 had no requirement to perform any kind of internal valve inspection or ground from The root cause operational check and no requirement to periodically replace the valves. The unauthorized of the large vacuum breaker valves were essentially installed as runto failure components.

release paths. volume leaks in There were no Technical Specification requirements or NRC commitments to 1998 and 2000 is conduct periodic maintenance. Prior to 1999, walkdowns of the blowdown documented in system were performed annually.

Root Cause Report (RCR) In July l 999, a preventive maintenance template from STANDARD NES-G-08, 38237, which CoinEd Performance Centered Maintenance (PCM) Templates, was adopted for determined that application~to the vacuum breaker valves. The particular template chosen is the Circulating specifically applicable to spring actuated safety relief valves, and contains no Water (CW) discussion of applicability to float type valves. The predefine task description is Blowdown "perform setpoint verification and seat leak check, or replace valve". The (B/D) Vacuum periodicity was set at 10 years. The template chosen was the closest match from Breaker (VB) all those available in the standard PCM template index.

Valves had inadequate . esign/Application -The barrier was challenged when system operation was D

preventative changed without changing the design or configuration of the vacuum breaker maintenance assemblies.

programs and inadequate Original CW blowdown system operation provided for controlling blowdown design flow using valves at the river screen house, thus the system would always configuration. remain full of water. This method of operation was abandoned within the first two years of operation due to repetitive failures of the control valves. Operation thereafter provided for controlling blowdown flow using valves located in the plant near the main condensers and when flow is secured, the blowdown line would depressurize and partially drain resulting in a potential pressure surge when flow was reinitiated. Discussion with the valve manufacturer revealed that if the valves are subjected to significant pressure surges, they should be equipped with surge protection. The current configuration had no surge protection. The reason why the system operation was changed rather than correcting the material condition of the valves at the river screen house was not pursued since that decision was historical. Similarly, the reason the change was made without considering impact on the vacuum breaker design/configuration cannot be determined.

On January 16, 2006, a leak occurred on VB-7 due to failure of an internal guide bushing and was documented on IR 00442540. EACE 442540 is performing an evaluation of this failure. The results of the EACE will be reviewed to determine if the findings in this root cause are still valid. Corrective Action 29 will track this issue.

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Cause (describe the cause and Problem identify whether it is a root cause or a Statement contributing cause) Basis for Cause Determination Causal Factor 2,

  • Although the corrective actions from the 38237 Root Cause Report were Root Cause 2 effective, the report did not address "small" spills because the need for a near The root cause zero leakage standard was not k"own or suspected. The near zero leakage of the small requirement was not identified in the 2000 Root Cause Report investigation due leaks, which to a lack of technical rigor/questioning attitude. For details, refer to Attachment both preceded 12.

and succeeded the 1998 and 2000 leaks, was that the need for a near zero leakage standard was not identified, due to a lack of Technical Rigor/Questionin g Attitude.

Inadequate Causal Factor 3,

  • After this root cause was identified, it was analyzed to determine if it was response to Root Cause 3: appropriate for this event. In other words, the team considered whether the unplanned The first root "why" question had been asked enough to adequately resolve the problem. The releases. cause for the team attempted to ask "why" and there is no clear/concrete documentation to ineffective explain why this 1990 procedure was not implemented (Failed Barrier, FB-4).

response was a Utilizing TapRoot analysis process, the root cause is the most basic cause (or lack of causes) that can be reasonably identified that management has control to correct integrated and when corrected, will prevent (or significantly reduce the likelihood of) the procedural issue recurring. In this event, Braidwood Senior Management has the ability to guidance to implement integrated procedural guidance to ensure thenecessary knowledge of ensure proper local hydrology, the impact of low-level tritium leaks, and groundwater recognition, regulations is directed to ensure consistent mitigation and remediation of future evaluation, and events. Thus, it was concluded that the root cause statement met the criteria of timely mitigation the TapRoot definition and it was appropriate for this event.

of the * (Failed Barriers FB 1 -17) (See Attachment 2) CSG-001 1990 (draft only) radiological spill contained guidance regarding underground transport mechanism for tritium and events. directions to remediate this pathway. Procedures for responding to and assessing radiological spills are either non-existent or inadequate. There was limited guidance to acknowledge 35 IAC 620 requirements or subsurface transport mechanisms to provide dose to the public. Failed barriers 1-17 address lack of integrated procedural guidance to ensure proper evaluation of the event, including knowledge of local hydrology, the impact of low-level tritium leaks, and groundwater regulations. This procedure contained instructions for mitigating intrusion of low-level radioactive spills into the groundwater. The reason the procedure was not implemented, could not be identified. Because this procedure did not provide overall integrated guidance for spill evaluation and mitigation, the failure to implement the procedure was not considered a root cause.

Therefore, the lack of integrated procedural guidance to ensure proper recognition, evaluation and timely mitigation of the radiological spill events was considered a root cause (Root Cause 3) for the ineffective response to Circulating Water (CW) Blowdown (B/D) Vacuum Breaker (VB) leaks (Causal Factor3, Root Cause 3).

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Cause (describe the cause and Problem identify whether it is a root cause or a Statement contributing cause) Basis for Cause Determination Inadequate Causal Factor 4, " In review of the 2000 Issues Management Team notes and other available response to Root Cause 4. documentation, the ineffective response from both the station and corporate unplanned A second root levels appears to have been due to a lack of clear delineation of specific releases. cause for the responsibilities during radiological spill response and remediation efforts.

ineffective Specifically, the interface of site and corporate Radiation Protection, Chemistry response was and Environmental departments are not clearly defined.

weak " Due to the cross discipline teams needed to respond /document a low level management radioactive leak and the lack of one procedure to integrate the response, CAPR review and 4 will ensure all aspects are covered.

oversight of spill response

  • Original 2000 root cause (38237) was too narrowly focused.

activities. " The Issues Management Team actions had no accountability or tracking through the CAP process.

  • Did not properly execute issue management procedures.

" Unaware of the 1991 State regulation regarding tritium limits.

A Senior Corporate Manager was chosen to assemble and direct the radiological remediation team. Four Corporate procedures which direct issues management were properly entered to identify, evaluate, remediate and communicate the radiological concerns. The four procedures include:

  • CWPI-NSP- I-I, "CAP Process Manual of Common Work PracticeInstructions

- Instruction on Event Response Guidelines"

  • OP-AA- 101-503, "NGG Issues Management".

However, no historical documentation could be located. to demonstrate that the procedures (other than NSP-RP-6101) were fully executed. This indicates weak execution of the spill remediation plan by the Issues Management Team and weak Braidwood Senior Management review and oversight of spill response activities. (Root

-Cause 4)

The water was pumped back into the B/D line on 11/10/00 and hydrology wells were installed in the area of the 2000 leak to characterize the local hydrology. Based on calculations and conclusions by a professional hydrologist, underground water in the area of VB-2 would take approximately 15 years to flow offsite. IDNS and EPA were informed. Further remediation efforts were not developed after the surface water was removed. Further efforts were limited to the mechanical failure oriented Root Cause Report (RCR) 38237 and the 10 CFR 50.75(g) characterization study. The 10 CFR 50.75(g) study did not sample groundwater for tritium, even though the NSP-RP-6101 procedure and the regulation clearly state to identify all radioisotopes (Failed Barrier 3). This procedure will be strengthened per CA 21. As a result, the groundwater tritium went undetected until the 2005 tritium sampling discovered the groundwater tritium.

This indicates weak Braidwood Senior Management review and oversight of spill response activities. (Root Cause 4)

See timeline for 2000 event, for further substantiation of needed improvements in Braidwood Senior Management oversight.

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Cause (describe the cause and Problem identify whether it is a root cause or a Statement contributing cause) Basis for Cause Determination Inadequate Causal Factor 5, Personnel were not aware of state regulations (35 IAC 620) to revise procedures and response to contributing training for these action levels. Additionally, those who would audit the ODCM/REMP unplanned cause. Personnel programs were also not aware that the regulatory and procedural deficiencies existed.

releases. were not aware (See Attachment 10) If the site had been aware of the requirement, then the site would of state likely have been driven to properly evaluate groundwater.

regulations (example: 35 IAC 620)

Causal Factor 6, (FB-30) Interviews with individuals indicated that notice to other Site Departments when Notification: an event occurred did not always occur. This was also observed through a review of the Processes and corrective actions database, which indicated that valve leakage was not always identified procedures for in CAP. In the current corrective action process at Exelon, all issues whether communication organizational or equipment related are entered and tracked in the corrective action not well defined, program.

(FB-31) Interviews with individuals indicated that a process for formal notification to the sites of State regulation changes is lacking. This was also observed through a review of applicable regulations and the lack of those regulations being consistently addressed in the ODCM, Reportability Manual, and other applicable procedures.

Causal Factor 7, Training does not exist for Operations, Chemistry or RP personnel for specific Training: responsibilities related to radiological spill response and assessment (reference General training Attachment 2) has no prompt to have personnel report environmental spills for assessment of radiological conditions.

Extent of Condition:

All Exelon Nuclear facilities are potentially affected, with added emphasis on Pressurized Water Reactors due to tritium production rates. A Nuclear Event Report (NER 428868-12) will require all Exelon Sites to take actions to research historical spills and determine if tritium remediation is required. The Nuclear Industry will be informed of the issue through a Nuclear Network Operating Experience Report (NNOE 428868-13). Other spill type (Hazardous Material) response procedures were reviewed and determined to have effective guidance through the Hazmat and Environmental programs (Attachments 2 & 8). These programs and procedures will receive further review and update to integrate radiological interfaces (CAPR 3).

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Cause being addressed Extent of Condition Review CF-I, RC-1, This condition applies to any site using a similar configuration for blowdown and radioactive release CAPR-1: Significant path. ATI 428868-13 was created to update the Nuclear Notification Operating Experience (NNOE) vacuum breaker leaks to communicate this issue to the Nuclear Industry. ATI 428868-12 was created to update the (NER) in 1998 and 2000. to communicate this issue to all Exelon sites. Issue Reports 00453379 and 00453387 document that Byron and LaSalle Stations have similar CW B/D and make up design configurations.

CF-2, RC-2, This issue applies to all Exelon Nuclear Stations. All sites produce tritium. Pressurized Water CAPR-2: Continuing Reactors produce a higher amount of tritium due to the usage of boron. ATI 428868-13 was created small vacuum breaker to update the Nuclear Notification Operating Experience (NNOE) to communicate this issue to the leaks after the 2000 Nuclear Industry. ATI 428868-12 was created to update the Nuclear Event Report (NER) to event. communicate this issue to all Exelon sites. Issue Reports 00453379 and 00453387 document that Byron and LaSalle Stations have similar CW B/D and make up design configurations.

CF-3, RC-3, This issue applies to all Exelon Nuclear Stations. All sites produce tritium that can possibly migrate CAPR-4 Procedures - into groundwater. Pressurized Water Reactors produce a higher amount of tritium due to the usage of A lack of integrated boron. ATI 428868-13 to update the Nuclear Notification Operating Experience (NNOE) to procedural guidance to communicate this issue to the Nuclear Industry. ATI 428868-12 was created to update the Nuclear ensure proper Event Report (NER) to communicate this issue to all Exelon sites.

recognition, evaluation, and timely mitigation of the spill events.

CF-4, RC-4, This issue applies to all Exelon Nuclear Stations since the review and oversight is controlled by CAPR-3 & 5: corporate procedures. Other spill type (Hazardous Material) response procedures were reviewed and Weak management determined to have effective guidance for non radiological programs (Attachment 8). These review and oversight programs and procedures will receive further review and update to integrate radiological interfaces.

of spill response CAPR 3 (Human Performance) and CAPR 5 (Issues Management) address these issues for all sites.

activities.

CF-5, Regulations: All sites have the potential for unplanned releases. The event at Braidwood station is one example.

Personnel were not There are numerous other nuclear industry events (OPEX) that resulted in groundwater aware of State contamination. For this reason, each site must assess the vulnerability of piping leaks and Regulations contaminating groundwater. This assessment is not limited to those plants that make liquid discharges. The concern is leakage into groundwater - not dose from liquid effluents to a defined outfall release point. Which is to say, that the ODCM does not direct routine measurements for leakage locations that may produce an exposure pathway. Issue Reports 00453379 and 00453387 document that Byron and LaSalle Stations have similar CW B/D and make up design configurations.

Corrective Actions 5 through 14 will address this vulnerability at each site.

CF-6, Notification: This issue applies to all Exelon stations. CAPR 4, CAPR 5, and CA-14 will address this Processes and vulnerability at each site.

procedures for communication not well defined.

CF-7, Training: This issue applies to all Exelon Nuclear Stations. ATI 428868-12 to update the Nuclear Event Report Personnel not all (NER) to communicate this issue to all Exelon sites.

aware of concern with CW B/D piping and secondary side effluents being tritiated water.

CW B/D vacuum Other Exelon/Amergen Nuclear sites were contacted to determine how those plants are configured breaker design for circulating water blowdown and makeup and if they have experienced any similar problems with vacuum breaker float assembly failures. Byron and LaSalle stations were the only stations confirmed to have circulating water blowdown and makeup systems that utilize vacuum breakers in their design.

For circulating water blowdown and makeup systems, the extent of condition is limited to Byron and LaSalle. Reference Byron IR 453379 and LaSalle IR 453387 for the respective site OPEX review.

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Risk Assessment:

Plant-specific nuclear Basis for Determination safety risk consequence None There are no plant specific risks associated with this issue. There are no risks to the CW Blowdown system as a result of this issue, since the leaking (failed) vacuum breaker assembly would still function o prevent a vacuum from forming and causing damage to the CW Blowdown piping. This issue has no impact for core damage/accident mitigation. The event was reportable under Reportability Manual, SAF 1.9, News Release or Notification of Other Government Agencies.

Previous Events:

The only previous event in terms of Braidwood's response to a release of a contaminant to the nearby environment would be PIF A2000-02683, Oil in North Runoff, where waste oil from an oil separator overflow entered a ditch which formed the boundary between Braidwood Station and Godley on the Station's west side. However investigation of this event by Braidwood Station and Illinois EPA did not identify any contamination of surface or groundwater in Godley. This event is listed in the table below as part of the discussion of events found in the search of the INPO web site.

Braidwood has identified 17 leaks from the Circulating Water Blowdown piping, and three of the events, 1996, 1998, and 2000, resulted in flooding of local areas. The previous events table contains a summary of leaks identified from records in the Corrective Action Program and the Work Control Process, including the Station's response. The majority of the blowdown leaks were small (as described in Table 1) and the water does not appear to have overflowed out of the vacuum breaker vault. However, to verify this, wells were drilled in the area of each of the Vacuum Breakers and tritium samples analyzed. The areas around VB-1, VB-2, VB-3, VB-4 and VB-7 have been verified to contain tritium. The entire length of the CW blowdown line has been tested for integrity and found to be intact, with no leaks above the minimum detection limit of 1.0 gpm.

The INPO website was searched for Operating Experience (OPEX) using the terms tritium, release, offsite, and groundwater. Passport was also searched using similar parameters.

There have been numerous events concerning unplanned releases to the environment at numerous sites. For the most part, the descriptions of the, events do not discuss remediation or continuing monitoring, but rather a statement that no activity was released from the site or detected offsite.

One instance (Pickering, 1997) was found where the licensee attempted to remediate the tritium in the groundwater by flushing the ground with fire protection water. This did not reduce the tritium concentration in the groundwater. Only one event (Waterford, 2003) reported detectable increases in offsite tritium due to a primary to secondary tube leak.

The 2000 overflow of a Braidwood oil separator was included because of its relevance in terms of potential impact to the public and station response.

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Operating Experience (OPEX) reports were reviewed. The OPEX reviewed did not reveal any missed opportunities to have prevented the events in this root cause report.

Braidwood Station had no known active leaks and had no increases in any routine radiological environmental samples when low level groundwater radioactivity due to tritium was discovered.

The following are summaries of relevant OPEX events in chronological order:

Previous Events Previous Event Review INPO Oyster Creek, 1-20-81 Condensate storage and radwaste transfer piping leaks resulted in underground release of radioactive liquid. No remediation was performed.

SER 4-81 Hatch, 12-3-86, OE1905, 124,500 gal from a spent fuel pool leak went into the storm drain system and eventually Operating Plant reached a swamp area within the owner-controlled property. The water discharge resulted Experience from a loss of air to the inflatable seals used in the transfer canal between the Units 1 and 2 Spent Fuel Pools. The area was decontaminated, and no activity was detected outside Georgia Power property.

Prairie Island, 5-1-92, Elevated levels of tritium (concentrations of 1, 300 to 1,500 pCi/L) were detected in an PNO3-92-023, Elevated onsite groundwater well. Offsite wells sampled showed no increase in-levels of tritium.

levels of tritium detected No further details or follow up actions have been issued on this Preliminary Notification in onsite well of Occurrence.

Dresden, 10-19-94, Degraded cathodic protection system and breached wrapping of underground piping OE7067, Cathodic results in through-floor pitting in both contaminated condensate storage tanks and three Protection System radwaste tanks between 1992 and 1994, through-wall pitting on the HPCI test return line Degeneration and a demineralized water line, and underground fire protection piping degraded in several areas. The leakage was characterized and a remediation plan to monitor the tritium plume was implemented. No documented review of OE 7067 could be found for Braidwood Station.

Pickering A, 7-18-97, Since 1979, groundwater at the upgrader plant Pickering A (UPP-A) has had tritium levels SER PD97184, Elevated in the surrounding groundwater that are above background. Several attempts have been Concentrations of Tritium made to reduce the tritium concentrations in the groundwater including pumping in Groundwater groundwater with low levels of tritium to the lake and flushing the area with fire protection water. Tritium concentrations in groundwater, however, remained constant.

Increased tritium is due to spills and unplanned releases and not taking appropriate action to remediate the area after spills or discharges.

Braidwood, 6-25-00, PIF Oil separator #1 overflowed into the north runoff and offsite. Root Causes were A2000-02683, Oil in inadequate preventative maintenance of the north runoff ditch and the oil separator.

North Runoff Remediation and offsite sampling was performed to mitigate and assess the impact to the public.

Limerick, 2-18-02, Event Tritium concentrations of 10000 pCi/L were detected in the normal waste holding pond.

Number 352-020215-1, There was no plant impact, no personnel exposure, and no release above regulatory limits Tritium Identified in to the environment. Groundwater monitoring is not performed.

Normal Waste Water Holding Pond and Auxiliary Boilers 29

I Previous Events Previous Event Review Prevous vens Prviou Evnt Rvie Salem, 9-18-02, Leakage from the Unit 1 Spent Fuel Pool as a result of clogged telltale drains was found.

OE15788, Spent Fuel To determine the affect of the leakage on site groundwater, 8 monitoring wells were Pool Leakage, and installed as reported on 3-19-03. Tritium results were as high as 69,200 pCi/L in one OE15859 Tritium sample, and positive results were found in 4 other wells. As reported on 7-25-03, sample Detected in Groundwater results obtained from new wells indicate tritium concentrations of 3.5M pCi/L and 125K Samples from Onsite pCi/L. Gamma scans of samples from both locations detected no other radionuclides.

Monitoring Wells There is no indication of any offsite release and there is no threat to the public or company (Follow-up to OE15788) employees. On 5-3-04, NRC Information Notice 2004-05: Spent Fuel Pool Leakage To Onsite Groundwater is issued describing the Salem event. Braidwood Station does not have any reasonable release paths from our spent fuel pool to the groundwater. The NER issued by Braidwood requires evaluation of all potential tritium spill paths.

Waterford, 2-28-03, Primary to secondary leakage from steam generator tube/tube plug degradation resulted in OE15894, Substantial an increase in secondary tritium levels and approached a reporting limit listed in the Rising Trend in Tritium Technical Requirements Manual (TRM) for a local drainage canal.

Activity Measured at (REMP) Sample Location at Waterford Dresden, 7-31-04, HPCI suction line had been leaking since Nov 2003. Up to 6M pCi/L was detected in CR248494, High Tritium monitoring wells and stormdrains on site. Hydrology study shows the event does not Activity In Onsite Wells affect residential wells near the site. Routine monitoring established for 1994 event had and Storm Drains been discontinued. Remediation consists of quarterly monitoring of plume as it dissipates, verifying it does not migrate off site.

Braidwood, 12-8-04, Site approaches ODCM quarterly dose limits of 7.5 mrem/unit following the AlR1 I OE19305 / OE19623, refueling outage due to failed fuel conditions. The cause of challenging the offsite dose Station Challenges limit is that the effluent release procedures and processes did not have limits or controls in Effluent Quarterly Dose place to account for failed fuel conditions.

Limits During Unit 1 Outage Watts Bar, 2-8-05, 550,000 pCi/L discovered during routine onsite environmental monitoring. No tritium has OE20318, Onsite been detected in water samples from offsite monitoring locations, public drinking Groundwater Tritium supplies, or the Tennessee River. Source is from a Cooling Tower Blowdown Line or Above Reporting Limits previous leakage from a temporary effluent line.

Indian Point, 9-1-05, Hairline cracks in the liner of the Unit 2 spent fuel pool are found. On 10-5-05 (Event OE21506 Spent Fuel Pool Report 42014), 21100 pCi/L of tritium was detected in monitoring well MW-111 located Hairline Crack in the Indian Point 2 transformer yard. Other wells showed negative. The sampling that was done was part of an ongoing investigation to verify and quantify previously identified leakage, potentially from the spent fuel pool. Continued sampling discovered tritium in 6 of 9 onsite wells.

Haddam Neck, 10-31-05, Spent Fuel Pool leakage to the site groundwater was discovered when removing soil east Event 42099 of the Spent Fuel Building. The quantity of water leaked is unknown. Estimates based on historic Spent Fuel Pool evaporation data indicate that the leak was small - on the order of a few gallons per day. Based on readings from down-gradient monitoring wells, there is no travel offsite.

30

Previous Events Previous Event Review EVENTS IDENTIFIED Description and review of event.

AT BRAIDWOOD STATION 12-5 A1998-04324, AR written Monday after Southern Div. PR contacted by neighbor. They sighted leaking CW Blowdown Vacuum vacuum breaker from the south was unaware of the "pond" to the north: Chemistry Breaker Leak - pond of contacted environmental services. AR status changed to B I due to possibly exceeding water found on property, release permit limits. This incident was initiated when (name removed) was contacted with standing water in about the pooled water by a local resident. (Name removed) and (name removed) road ditch along Smiley investigated and noted the pool was located on station property. There was minor Rd. puddling in the adjacent ditch but this water did not run off. Environmental services were consulted and since the ponded area was restricted to station property there was no NPDES concern. The blowdown system was shut down to isolate the vacuum breaker and stop the leakage. WR 980127749 was written to repair the vacuum breaker. The work was performed over the weekend of 12/5. The station response to this event was excellent. Maintenance had this repaired in -24 hrs. This failure had prevented the station from performing liquid releases.

11-7 A2000-04281, The valve had been in this condition for an unknown period of time, most likely several Failed Circulating Water days. The ground in the nearby area is sandy and drains quickly. The ground was Blowdown Vacuum saturated with water. Upon the discovery of the leak operations isolated CW blowdown Breaker Caused on the afternoon of 11/6/2000. Draining of the piping to affect the repairs was started on Unplanned Flooding the morning of 11/7/2000. The 0CW135 (manual isolation to 0CW136) and the 0CW136 Outside the Power Block - CW blowdown vacuum breaker valve were replaced with new valves by 1600 hrs 0CW136 CW blowdown 1 1/7/2000. Once a year a visual inspection of the blowdown and make up lines is valve was found leaking performed, including the vacuum breakers. The float in question is an internal part and past its main seat. cannot be inspected without disassembly of the valve. A degraded condition could be found by noting some leakage past the valve seats. This is the first failure of this type. A schedule of replacements will be proposed to the PHC by the system engineer to prevent reoccurrence. Extent Of Condition: the same/similar valve is used in several places on the CW make up and blowdown piping. Byron has a CW makeup and blowdown pipe, however it is not known if Byron has vacuum breakers and if so what type of vacuum breakers. A message was left for the Byron CW system engineer about this problem.

11-17 A2000-04389 The station's response to a December 1998 CW vacuum breaker valve (OCW060) failure (39223), Inadequate appears to have been inadequate. No evidence can be found to documenting any follow-response to 1998 CW up sampling, surveys or reporting requirements. PIF# A 1998-04324 details the station' vacuum breaker valve, response to the 1998 leak. This issue was discovered during the present root cause leak. investigation for the CW vacuum breaker valve failure (OCWI136).

11-30 A2000-04465, Station was slow to implement event response guidelines, CWPI-NSP-AP-1-1, or NGG Slow response to Issues Management, OP-AA-101-503, for the CW blowdown vacuum breaker failure that implementing Event was discovered on 11/06/00. NGG Issues Management was not entered until 2+ days Response after discovery of the valve failure when rad sample results indicated detectible levels of Guidelines/NGG Issues particulate radioactivity from the spill.

Management procedure.

6-18 A2001-01806, Unauthorized Release Path? [#3 & 11 ]- OCW060 was found seeping water from between CW B/D Valve Leaking. the vacuum breakerfloat and the Buna-N seal. Leakage appears to be about I gal/2 hours.

As discovered during the investigation of CR# A2000-04281, periodic maintenance of the circulating water blowdown vacuum breaker valves had not previously been up to the standards desired by the station. A campaign was initiated in Q2 2001 to repair/replace as necessary these vacuum breaker valves. When the vaults were opened, four were discovered to contain water (vaults housing OCW060, 0CW144, 0CW075 and 0CW078).

Radiological analysis of the water revealed 2 of the 4 vaults with radioactive material present in the water (OCW060 and 0CW078 showed activity).

31

Previous Events Previous Event Review 7-9 A2001-02016 A review of a root cause report titled "Circulating Water Blowdown Line Vacuum (56710), Weaknesses Breaker Failure Due To Low Stress, High Cycle Fatigue, Resulting In Flooding Of Owner Identified in Controlled Property And Discharge Outside Of NPDES Approved Path" determined that Documentation of RCR there were weaknesses associated with the report documentation (reference CR# A2000-For CW Blowdown 04281 .and ATI# 38237). Although the report was well written, the review identified that Valves. the description of the Corrective Actions to PreventRecurrence (CAPRS) lacked the clarity needed for mechanical maintenance to understand the full scope of work required to execute the CAPR. Furthermore, it appears that scheduling issues were not fully considered when the due dates were set.

5-4 106767, Small OCW060, CW blowdown vacuum breaker, was identified as having seepage from the vent leak identified from on the air release valve, (air release valve is part of the entire vacuum breaker assembly OCW060 blowdown valve but sits adjacent to the main vacuum breaker valve). Main vacuum breaker valve assembly (VB-3) appeared satisfactory, no leakage. Water level in pit was 30" from top of manhole. No evidence of leakage outside of the manhole was noticed. Water in manhole/pit appears to be a normal condition associated with groundwater infiltration into the manhole.

8-20 172376, CW Main vacuum breaker seat has 1 gpm leak. Water is draining to vacuum breaker pit only Blowdown Vacuum no area flooding is occurring.

Breaker 0CW138 has 1 gpm leak (VB-4) 8-27 173204, Modification testing associated with EC336241 was performed on 8/25/03. The testing OWX26T release with required a release to be performed from the OWX26T release tank while blowdown flow suspected leakage from was established at -25,000 gpm. Seat leakage from the 0CW138 blowdown vacuum OCW138 VB-4. breaker most likely occurred during the time that blowdown flow was at a flow rate of 25,000 gpm. Based on field observations performed on 8/21/03 and 8/27/03 the suspected leakage from the OCW 138 during the time of the OWX26T release was between .25 and 1 gpm, (Note: 0WS26T release occurred between 0630 and 0710 on 8/25/03, Release package L03-104.) Field observations of the 0CW138 were also performed at blowdown flow rates of between 12,000 & 14,000 gpm. These observations indicate that no leakage occurs at these lower flow rates and that the vacuum breaker appears to be open, (Note:

OCW138 open with no leakage indicates that the blowdown pipe is not completely full at the lower flow rates.)

8-29 173688, Water While performing the annual vacuum breaker surveillance we discovered water in the pit in Vacuum Breaker Pit for containing breaker OCW060. WR # 00110407 was initiated.

breaker OCW060 [#3].

9-11 175241, When CW blowdown was increased per BwOP CW- 12 (to approximately 22,000 gpm, 0CM138 leaking at high 0CW138 was discovered to be leaking at 5 drops per minute.

CW blowdown flow rates

[#4].

11-17 274328, While performing OBwOS CW-A1 (CW System B/D and M/U Vacuum Breaker Vacuum Breaker Inspection) vacuum breaker 0CW069 was popping/leaking. The leakage was small and 0CW069 Is Leaking [#8]. contained within the vacuum breaker's valve pit. Per the Limitations and Actions of the procedure the Shift Manager and RP were notified immediately. Chemistry was notified of the potential for exceeding a limit for NPDES. System Engineering was contacted for guidance and it was determined that the 0CW068 valve would be maintained closed to isolate the vacuum breaker leakage. The System Engineer recommended that two adjacent vacuum breakers not be isolated with CW blowdown in operation. EST (37096)

(Equipment status tag) was generated to document the abnormal position.

32

Previous Events Previous Event Review 4-25 328451, Tritium Two samples results from onsite property located on the downstream side of the culvert at Indicated In Samples the old A entrance gate came back from the vendor with tritium indicated on the results.

Taken From Onsite Specifically, the analysis results from Environmental Inc. Midwest Laboratory (EIML)

Culvert. indicated results of 539 +/-121 pCi/L tritium (sampled on 03/24/05) and 582.963 +/-

112.314 pCi/L tritium (sampled on 04/07/05).

5-18 336401, CW CW BD Vacuum breaker 0CW058 pilot valve leaking 20 DPM. Need WR to repair.

BD Vacuum Breaker 0CW058 Pilot Valve Leaking 20 DPM [#1].

5-24 338111, While performing ER-BR-400-101, OCW 140 blowdown vacuum breaker valve was OCW140 Blowdown observed to have continuous seepage of water from the valve float/seat area. The leakage Vacuum Breaker Valve is small enough to be contained within the vacuum breaker valve pit with approximately Leaking From Seat [#6. one foot of standing water in the pit.

9-8 371248, NRC During NRC debrief on 8/31/05, there was discussion regarding the CW blowdown Questions On Previous vacuum breaker, 0CW058, leakage that was identified in May 2005 (Reference IR Actions With CW B/D 336401). A previous root cause was performed for vacuum breaker failures that occurred vacuum breakers. in 2000. The NRC question is: Subsequent to 0CW058 leakage identified in May 2005, were the root cause actions reviewed for adequacy? If so, what was the conclusion?

11-30 428868, Elevated levels of tritium have recently been identified in certain onsite groundwater Elevated Tritium Levels sampling wells. The exact source has not been located nor has the source been In Onsite Monitoring determined to be active or historical.

Wells.

NOTE: Review was revalidated on 02/16/06 with no new relevant events found.

33

Corrective Actions to Prevent Recurrence (CAPRs):

Root Cause Being Corrective Action to Prevent Recurrence Owner Due Date Addressed (CAPR)

Causal Factor 1, Root (CAPR 1: ATI# 38237-08, 38237-17, & 38237-18) A8930I" Completed Cause 1: The root cause Institute a Preventative Maintenance Program and 03/01/01 of the significant leaks in system modifications, which are complete and have 1998 and 2000 is been verified to be effective in preventing major valve documented in Root failures that result in large volume spills.

Cause Report (RCR) 38237, which determined [NOTE: On January 15, 2006, a leak occurred on VB-that the Circulating Water 7 due to failure of an internal guide and was (CW) Blowdown (B/D) documented on IR# 442540. (See analysis section of Vacuum Breaker (VB) how this issue is addressed) CA-29 will review EACE Valves had inadequate 442540 to ensure corrective actions from 2000 RCR preventative maintenance 38237 & RCR 428868 are still effective.]

programs and inadequate design configuration. Braidwood Station presently performs daily walkdowns of the blowdown vacuum breakers to verify Failed Barrier (FB- 20) that no leakage is occurring.

Piping/Valves equipment failures Causal Factor 2, Root (CAPR 2) 1) A8901H3 1) 04/03/06 Cause 2: The root cause 1) The Braidwood Tritium Remediation Team will of the small leaks, which determine the methodology and implement the plan for both preceded and future radiological releases, including leakage succeeded the 1998 and standards. (Note: AR 435383435383 2000 leaks, was that the need for a near zero (CAPR 3) 2) A8923 and 2) Completed.

leakage standard was not 2) HU-AA- 102 and HU-AA- 1212, Technical Human A8961 (approved (Approved for identified, due to a lack of Performance Practices and Technical Task Risk/Rigor for use at use at Technical Assessment, Pre-Job Brief, Independent Third Party Braidwood) Braidwood in Rigor/Questioning Review, and Post-Job Brief procedures have been 07/09/04 and Attitude. instituted to improve technical rigor, questioning 07/14/04) attitude, and attention to detail.

CF-5 Regulations/Oversight FB-33 Weak management review and oversight of spill response activities.

34

Root Cause Being Corrective Action to Prevent Recurrence. Owner Due Date Addressed (CAPR) OwnerDueDat Causal Factor 3, Root (CAPR 4) NCS 6/20/06 Cause 3: Develop and implement Standard Exelon procedures to A8015ENV The first root cause for provide integrated and detailed spill and leak response the ineffective response requirements to ensure full compliance with State and was a lack of integrated . Federal laws and regulations and integrate Exelon procedural guidance to resources to respond to radiological leaks and spills.

ensure proper recognition, evaluation, and timely mitigation of the radiological spill events.

CF-3 Procedures Failed Barrier (FB)-l BwAP 750-4 FB-2 BwAP1 100-16 FB-3 NSP-RP-6101 FB-4 RP-AA (no specific procedure)

FB-6 BwOA ( no specific procedure FB-12 ER-BR-400-101 FB-13 OBwOS CW-A1 FB-14 EN-AA Causal Factor 6 Notification FB-30 Notification to other site departments Causal Factor 4, Root (CAPR 3) 1) A8923 and 1) Completed Cause 4. A second root 1) HU-AA-102 and - HU-AA-1212, Technical Human A8961 (approved (Approved for cause for the ineffective Performance Practices and Technical Task Risk/Rigor for use at use at response was weak Assessment, Pre-Job Brief, Independent Third Party Braidwood) Braidwood in management review and Review, and Post-Job Brief procedures have been 07/09/04 and oversight of spill instituted to improve technical rigor, questioning 07/14/04.

response activities, attitude, and attention to detail.

(CAPR's 3 and 5)

(CAPR 5) 2) A8016NGGOP 2) 04/21/06 CF-5 2) OP-AA-106-101-1002, Exelon Nuclear Issues Regulations/Oversight Management, will be revised to: 1) improve Corrective FB-33 Weak management Action Program (CAP) controls of Issues Management review and oversight of teams, 2) utilize the tools and techniques of the Exelon spill response activities. HU-AA-102 and HU-AA-1212, Technical Human Performance Practices and Technical Task Risk/Rigor Assessment, Pre-Job Brief, Independent Third Party Review, and Post-Job Brief procedures, 3) strengthen reporting requirements to affected station Senior Management, and 4) define affected station Senior Management responsibilities for oversight and challenge of events and issues from initial identification to final disposition.

35

Effectiveness Reviews (EFRs):

Effectiveness CAPR / CA being addressed Review Action Owner Due Date Causal Factor 1, Root Cause 1: The root cause of the (EFR 1: 00038237-10) A8930Tr Completed significant leaks in 1998 and 2000 is documented in Perform effectiveness 05/22/2002 Root Cause Report (RCR) 38237, which determined review of CAPR's under that the Circulating Water (CW) Blowdown (B/D) ATI# 00038237-Vacuum Breaker (VB) Valves had inadequate 7,8,10,17-20 preventative maintenance programs and inadequate design configuration.

EFR assignment for CAPRs # 2, 3, 4, & 5: EFR 2 A8932CHEM 6/20/07 (CAPR 2) The Braidwood Tritium Remediation Team Perform effectiveness will determine the methodology and implement the review of CAPR(s) under plan for future radiological releases, including leakage ATI#428868 for CAPR#

standards. 2,3,4,5 (CAPR 3) HU-AA-102 and HU-AA-1212, Technical Human Performance Practices and Technical Task Risk/Rigor Assessment, Pre-Job Brief, Independent Third Party Review, and Post-Job Brief procedures have been instituted to improve technical rigor, questioning attitude, and attention to detail.

(CAPR 4) Develop and implement Standard Exelon procedures to provide integrated and detailed radiological spill and leak response requirements to ensure full compliance with state and federal laws and regulations and integrate Exelon resources to respond to radiological leaks and spills.

(CAPR 5) OP-AA-106-101-1002, Exelon Nuclear Issues Management, will be revised to: 1) improve Corrective Action Program (CAP) controls of Issues Management teams, 2) utilize the tools and techniques of the Exelon HU-AA- 102 and HU-AA- 1212, Technical Human Performance Practices and Technical Task Risk/Rigor Assessment, Pre-Job Brief, Independent Third Party Review, and Post-Job Brief procedures, 3) strengthen reporting requirements to affected station Senior Management, and 4) define affected station Senior Management responsibilities for oversight and challenge of events and issues from initial identification to final disposition.

MRC assignment for EFR CA-1 A8932CHEM 6/27/07 Present the EFR to MRC.

36

Corrective Actions:

Cause Being Addressed Corrective Action (CA) or Action item (ACIT) Owner Due Date Causal Factor 5 CA-2 A8961 08/30/06 Regulations/Oversight Develop a case study of this event. Provide initial and Failed Barrier (FB-33) continuing training for appropriate Braidwood Station and Weak management Exelon Corporate Management personnel.

review and oversight of radiological spill CA-3 A8961 07/21/06 response activities. Generate a training request for Dynamic Learning Activity (DLA) for all Braidwood Duty Team personnel using 2000 release conditions and revised response and reporting procedures implemented in CAPR4. Create additional assignments as warranted. Report training request action determinations to STC.

CA-4 NCS 05/29/06 Generate a training request to review other potential leaks A8076CHEM beyond tritium to address extent of condition regarding Exelon management's control of hazardous material spills.

If deficiencies are noted, write IR's to have those deficiencies addressed. Report training request action determinations to STC.

Causal Factor 5. CA-5 NCS 05/29/06 Regulations/ Oversight Revise the Midwest ODCM and/or program procedures to A8076CHEM FB-27 Title 35 IAC incorporate the State of IL requirement of <20,000 pCi/L part 620 groundwater of tritium for groundwater (35 IAC 620.410.e).3)) and the quality State of IL requirement for non-degradation (35 IAC 620.301.a))

CA-6 NCS 05/29/06 Revise the ODCM and/or program procedures as A8076CHEM warranted to incorporate the State of PA requirements for radioactivity in groundwater.

CA-7 NCS 05/29/06 Revise the ODCM and/or program procedures as A8076CHEM warranted to incorporate the State of NJ requirements for radioactivity in-groundwater CA- 8 NCS 05/29/06 Clearly define to each station (extent of condition), the A8076CHEM changes to the ODCM based on review of Illinois laws governing radioactive contamination of groundwater (potable water). Assign additional corrective actions to ensure site's ODCM reflects and implements applicable regulations.

CA-9 NCS 05/29/06 Clearly define to each station (extent of condition), the A8076CBEM changes to the ODCM based on review of Pennsylvania laws governing radioactive contamination of groundwater (potable water). Assign additional corrective actions to ensure site's ODCM reflects and implements applicable regulations.

37

Cause Being Addressed Corrective Action (CA) or Action item (ACIT) Owner Due Date Causal Factor 5. CA-10 NCS 05/29/06 Regulations/ Oversight Clearly define to each station (extent of condition), the A8076CHEM Failed Barrier (FB)-27 changes to the ODCM based on review of New Jersey Title 35 IAC part 620 laws governing radioactive contamination of groundwater groundwater quality (potable water). Assign additional corrective actions to ensure site's ODCM reflects and implements applicable regulations.

Causal Factor 3, CA- 1 NCS 05/29/06 Procedures Corporate Regulatory Assurance to perform an extent of A8002RAPO condition review regarding ODCM, REMP, RETS and FB-7 LS-AA-1020 & state regulations for needed changes to the Reportability 1110 Reportability Manual and create additional actions as required.

Manual CA-12 NCS 4/14/06 FB-8 LS-AA-1020 & Corporate Regulatory Assurance to revise the A8002RAPO 1110 Reportability Reportability Manual for reporting requirements of 35 Manual IAC 611/620 Groundwater Tritium Release Path, 20,000 pCi/L limitations, and Illinois SB241 Community Right to FB-9 LS-AA-1020 & Know requirements.

1110 Reportability Manual Causal Factor 5, CA- 13 NCS 06/28/06 Regulations/ Oversight Revise CY-AA-170-000 and associated procedures to A8076CHEM require audits of the ODCM against applicable laws and FB-28 Corporate regulations at.an acceptable frequency. Review the need Oversight for revision to include State regulations into Step 4.2.1 basis of the ODCM. Create additional actions as warranted.

Causal Factor 3, CA-14 NCS 4/14/06 Procedures Review the process by which the company becomes aware A8015 ENV FB-1 1 LS-AA-1020 & of new environmental laws and regulations for 1110 Reportability radiological and non-radiological issues and how they are Manual integrated and communicated into company policies, programs, and procedures. Assign additional actions as necessary, if process changes are needed.

Causal Factor 5, Regulations/Oversight FB-26 Title 35 IAC part 611 groundwater quality FB-27 Title 35 IAC part 620 groundwater quality Causal Factor 6, Notification FB-31 Notice to sites of new State Regulations 38

Programmatic/Organizational Issues:

Programmatic and Organizational Corrective Action (CA) or Action Item (ACIT) Owner Due Date Weaknesses Causal Factor 5, CA 15 NCS 5115/06 Regulations/Oversight Evaluate the groundwater and food crop pathway per A8076CHEM ODCM Table 12.5-1 Section 3.a note (6). Assign Failed Barrier (FB)-24 additional actions as necessary, if the pathway is ODCM requires credible.

evaluation of groundwater pathway if CA 16 NCS 5/15/06 credible Revise the Site specific portions of the ODCM to A8076CHEM incorporate the new monitoring wells as determined by FB-25 ODCM requires the ODCM Environmental Specialist to be credible evaluation of groundwater (well water) monitoring sources into the groundwater pathway if ODCM Table 11-1 Section 3.a note (6) and ODCM credible REMP Table 12.5-1 Section 3a Note (6).

Causal Factor 7, Training CA 17 A8931RP 3/14/06 Generate TR to develop appropriate training for the RP FB-21 Certification of management and technician level of knowledge Chemistry personnel regarding the CW B/D system and the radioactivity expected to be present. Refer to the Root Cause Report FB-22 Licensed and to be used as a case study. If the TR is rejected, report Non-licensed Operator out to Senior Training Council (STC).

initial and requalification CA 18 A8932CHEM 3/14/06 training Generate TR to develop appropriate training for the chemistry management and technician level of FB-23 Certification of knowledge regarding the CW B/D system and the RP/HP radioactivity expected to be present. Refer to the Root Cause Report to be used as a case study. If the TR is rejected, report out to Senior Training Council (STC).

CA 19 A8910OPS 3/14/06 Generate TR to develop appropriate training for the operations personnel level of knowledge regarding the CW B/D system and the radioactivity expected to be present. Refer to the Root Cause Report to be used as a case study. If the TR is rejected, report out to Senior Training Council (STC).

Causal Factor 3, CA 20 A8910OPS 5/29/06 Procedures Ops to add precautions to BwOP CW-12, BwOP WX 526TI, & BwOP WX-501TI for release shutdown on FB-15 BwOP CW-12 leak to environment and for the release restrictions FB-16 BwOP WX-526T1 dealing with Reportability Manual Section RAD 1.21 FB-17 BwOP WX-501T1 (i.e.: 100 Ci. limit on tritium releases over a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period).

Causal Factor 3 CA 21 A8931RP 6/1/06 Procedures: RP manager to present to peer group changes to FB-3, NSP-RP-6101, 50.75(g) procedure to clearly address actions necessary "10 CFR 50.75(g)(1) for tritiated water spills, including evaluation for dose Documentation assessment to the public and initiate follow-up actions Requirements" as appropriate to track necessary procedure changes.

39

OTHER ISSUES:

Other Issues Identified During the Investigation Corrective Action (CA) or Action Item (ACIT) Owner Due Date Other issues: Alarms/ CA-22 A8930TT 03/24/06 Annunciators Braidwood System Engineering to review operation of IR435383 the CW. blowdown system and determine the optimum Failed Barrier (FB)-I 8 monitoring scope and frequency of inspection PM's Leak detection of and walk downs for the System. If applicable, identify vacuum breakers gaps and create additional ATI's as required.

Other issues: CA-23 A8930TI 07/14/06 Alarms/Annunciators Braidwood System Engineering to research and IR435383 evaluate passive vacuum breaker replacement options FBý18 Leak detection of and present findings to PHC for approval if the CW vacuum breakers Blowdown system will be used for radwaste releases in the future. If no action is taken, present this fact to MRC.

Other issues: Alarms/ CA-24 A8930TT 07/14/06 Annunciators System Engineering to work with Design Engineering IR435383 to research and evaluate viable remote monitoring FB-19 Alarms and instrumentation systems that can detect lower level Annunciators external leakage from the blowdown system and automatically notify Braidwood Operations if the CW blowdown system will be used for radiological releases. If no action is taken, present this fact to MRC.

Other issues: Work CA-25 A8931RP 3/10/06 Orders: RP to provide information to Work Planning so that a work standard can be created for work activities that FB-32 involve potentially tritiated water. This information Model PM work orders will be used to update PM model work orders and and current work orders current work orders involving potentially tritiated for B/D vacuum water.

breakers Causal Factor 3 CA-26 NCS 5/29/06 Procedures Corporate Work Control to implement revision of WC- A8035OUT AA- 106 to incorporate a higher work priority for FB-5 response to unplanned low-level radioactive water WC-AA-106 being released to the environment and repairs to Attachment I implies a release path monitors.

"B2" if increased sampling Other issues: Work CA-27 A8925PLN 4/10/06 Orders Using the information provided by RP, create a work standard to be used for work activities that involve FB-32 Model PM work potentially tritiated water and update PM model work orders and current work orders and current work orders involving potentially orders for B/D vacuum tritiated water (RWP, sample for tritium, instructions breakers for pumping tritiated water).

40 C-

Other Issues Identified During the Investigation Corrective Action (CA) or Action Item (ACIT) Owner Due Date Causal Factor 6, ACIT-28 A8921NOA 03/28/06 Notification Discuss this RCR with the Corporate NOS Peer Group to evaluate changing the NOS auditing template Failed Barrier (FB)-29 standard for the ODCM Program. Document results NOS Audit NOSA- and assign additional actions as required.

BRW-05-08 (AR 287718287718 November 22, 2005 Causal Factor 1, Root CA-29 A8930T" 03/28/06 Cause 1 Review EACE 00442540 to ensure corrective actions from 2000 RCR 38237 & RCR 428868 are still effective Causal Factor 3, CA-30 A8931RP 11/28/06 Procedures Review 50.75(g) files to ensure tritium and or any other isotopes are included for all blowdown vacuum FB-3 NSP-RP-6101 breaker water events and perform 50.75(g) evaluation for all blowdown vacuum breakers not previously completed.

Other issues: Procedures CA-31 A8930TT Per CA BwOP CW-12 was revised to undo water hammer process FB-20 Piping/valves corrective actions from the 2000 root cause report.

equipment failures Issue to be addressed under IR 45338 1.

01 fl, ODCM IR 453638 Tritium Remediation Team review the A8901H3 4/01/06 Reportability review for reportability associated with 12.5.1lA.2 to determine environmental samples applicability to the environmental groundwater sampling that is occurring as part of their investigation.

01 gI, No clear CA-32 NCS 6/20/06 delineation of Update Exelon Management Model to define A8015ENV responsibilities between responsibilities for low level radioactive spills.

corporate Environmental and Chemistry for low level radioactive spills.

41

Communications Plan:

Lessons Learned to Communication Plan Action Owner Due Date be Communicated Elevated tritium levels in NER 1 A8932CHEM Complete onsite monitoring wells; Submit Preliminary NER (NER 1) for this event Elevated tritium levels in NNOE 1 A8932CHEM Complete onsite monitoring wells; Submit preliminary NNOE (NNOE 1) for this event.

Blowdown line, CA 33 A8932CHEM 03/14/06 Secondary System Create a station alignment slide that discusses the root Condensate and other cause and actions for station personnel when they low level tritium system discover liquid spills/leaks or liquid in areas where-leaks impact to State and there should not be liquid.

Federal regulations for ground/drinking water.

Elevated tritium levels in NER update (NER 2) per ATI 428868-12 A8932CHEM 03/03/06 onsite monitoring wells; Submit supplemental NER (NER 2) for this event Spills of liquids with low which include a requirement for all Exelon sites to; level radioactivity may 1) Review all historical radiological spills/leaks to site impact State and Federal property outside of the RCA.

regulations. 2) Verify tritium concentrations have been determined for the radiological spills/leaks or perform sampling to determine tritium concentrations for each of the radiological spills/leaks.

3) Determine impact of spilled tritium on environment.
4) Create additional actions as warranted to insure compliance with all Federal and State regulations and laws.

Elevated tritium levels in Promulgate NER 2 to Exelon Nuclear Fleet to include: A8076CHEM 03/13/06 onsite monitoring wells; Submit supplemental NER for this event which include Spills of liquids with low a requirement for all Exelon sites to; level radioactivity may 1) Review all historical radiological spills/leaks to site impact State and Federal property outside of the RCA.

regulations 2) Verify tritium concentrations have been determined for the radiological spills/leaks or perform sampling to determine tritium concentrations for each of the radiological spills/leaks.

3) Determine impact of spilled tritium on environment Elevated tritium levels in NNOE update (NNOE 2) per ATI 428868-13. Submit A8932CHEM 03/10/06 onsite monitoring wells; supplemental NNOE (NNOE 2) for this event Spills of liquids with low level radioactivity may impact State and Federal

-regulations.

42

Root Cause Report ATTACHMENTS

  1. Title Notes 1 Charter Revision 1 for improved scope clarity.

2 Barrier Analysis 3 Cause & Effect Analysis 4 E&CF Chart 5 Change Analysis 6 Circ water blowdown system background information 7 Tritium plume map 8 Review of Exelon Hazmat spill response procedures 9 Reportability Manual - LS-AA-1020 and LS-AA-1110 10 Summary of Applicable State, Federal, and Offsite Dose Calculation Manual (ODCM)

Regulations and Requirements for Tritium Releases to the Environment 11 Root Cause Report Quality Checklist 12 VB-2 and VB-3 detailed timelines 43

Attachment 1 Page 1 of 3 LS-AA-1 25-1001 Revision Root Cause Investigation Charter (rev 1)

Tritium Release from Braidwood Station with a Potential to Affect the Public Condition Report #: 428868 Sponsoring Manager: Janice Kuczynski, Chemistry Manager Team Investigator(s):

Names Position Commitment

.,Jason Eggart Braidwood Chemistry Lead Investigator Full Time

'Tom Leffler Root Cause Qualified Investigator Full Time Randy Kalb Dresden Chemistry Investigator Part Time IKim Aleshire Braidwood EP (ODCM) Investigator Full Time Glen Vickers LaSalle RP Investigator Full Time Scott Kirkland Quad Cities Investigator Part Time Jim Crawford Braidwood Maintenance Investigator Full Time John Gumnick Corporate RP (CHP) Investigator Part-Time Mike Miller Braidwood Operations Part Time Jeff Burkett Braidwood Operations Part Time

)Dan Stroh Braidwood Engineering Full-Time

,Scott Sklenar Hydrologist Part-Time Scope:

The scope of the root cause investigation is twofold:

The first focus of this root cause team is to determine the root cause(s) of the Tritium releases from Braidwood Station, which, although low level, had a potential to affect the public. This causal determination should include the large volume leaks, which occurred in 1998 and in 2000, as well as the smaller volume leaks, which both followed and preceded the 1998 and 2000 leaks. The responsibility for identifying and operationalizing corrective actions to prevent future unacceptable tritium releases to the environment is being addressed by the Braidwood Tritium Remediation Team under AR 435383435383

44

Attachment 1 Page 2 of 3 This root cause team remains responsible for identifying corrective actions to address organizational weaknesses contributing to or causing the releases described above.

The second focus of this root cause team is to evaluate the effectiveness of Braidwood's response to the circulating water Blowdown leaks, which deposited tritiated water on the ground during 1998 and 2000 as well as during the smaller volume leaks, which both followed and preceded the 1998 and 2000 leaks. If this evaluation determines that Braidwood's response actions were not effective, this root cause team will determine the root cause and appropriate corrective actions for those ineffective response actions. The investigation will review response procedures, regulations, environmental impacts, and managerial effectiveness. As part of this second focus item, the team will review the response to known spills in 1998, 2000 and similar IRs. A review of year 2000 Root Cause corrective action effectiveness will be performed. Specifically, the team will look for any evidence that the actions to prevent recurrence were not effective. An E&CF Chart will be utilized for Change Analysis and Barrier Analysis. Tap Root Analyses will also be utilized.

To accomplish a timely report delivery, support will be required as noted above in Engineering, Hydrology, Maintenance, Operations, Offsite Dose Assessment, and Technical Writing.

The responsibility for remediating the existing condition of detectable tritium in groundwater on and in the vicinity of Braidwood Station is not the responsibility of this root cause team. Remediation of the existing condition of detectable tritium in groundwater on and in the vicinity of Braidwood Station is being addressed by the Braidwood Tritium Remediation Team under AR 435383435383

Interim Corrective Actions:

As described above, an Issues Management Team (the Braidwood Tritium Remediation Team) has been formed to manage the recovery.

Additional Sampling is being performed and analyzed to fully define the affected areas.

The discharge piping is being reviewed for integrity.

Remediation plans will be developed and implementation initiated.

The Braidwood Tritium Remediation Team will maintain communications with Exelon, Regulatory personnel, the public, and INPO.

45

Attachment 1 Page 3 of 3 Root Cause Report Milestones:

1. Event Date (11/30/05)
2. Screening Date (12/07/05)
3. Completion of Charter (2 Days from MRC) [-03] (12/09/05) 3a. Completion of Charter revision (02/08/06)
4. Status Briefing for Charter [-14] (12/14/05)
5. Two Week Update & Draft RCR for Reviews [-07] (12/21/05)
6. MRC Update & Draft RCR for Reviews [-08] (12/28/05)
7. CAPCo Reviews of RCR [-15] (12/29/05)
8. Collegial Reviews of RCR [-15] (12/29/05)
9. MRC Update & Draft RCR for Reviews [-09] (01/04/06)
10. Sponsoring Manager Report Approval [-14] (01/04/06)
11. Root Cause delivered to PORC (01/24/06)
12. Review by PORC [-05] (01/26/06)
13. Revised Root Cause Report delivered to PORC (02/20/06)
14. Revised Root Cause Report Reviewed by PORC (02/22/06)
15. Final Root Cause Investigation Due Date [-04] (02/23/06)

Prepared By:, Tom Leffleri Root Cause Qualified 02/06/06 1,vestigatov (Name) (Date)

Approved Carl B. Dunn, Training Director 02/08/06 By:

For (Sponsoring Manager) (Date) 46

Attachment 2 Page 1 of 11 Barrier Analysis Failed or ineffective barrier How Barrier Failed Why Barrier Failed Corrective action to Restore Barrier to Effectiveness Procedures CF 3_

BwAP 750-4 - Hazmat was not Lack of knowledge of - Develop and implement Standard Exelon procedures to provide integrated and entered Title 35 IAC part 620 detailed spill and leak response requirements to ensure full compliance with state Failed Barrier 1 groundwater quality and federal laws and regulations and integrate Exelon resources to respond to (FB-1) radiological leaks and spills. (CAPR 4)

- Procedure does not - See Training Failed Barrier actions prompt radiological response BwAPll00-16 - Hazmat was not Lack of knowledge of -Develop and implement Standard Exelon procedures to provide integrated and (FB-2) entered Title 35 IAC part 620 detailed spill and leak response requirements to ensure full compliance with state groundwater quality and federal laws and regulations and integrate Exelon resources to respond to radiological leaks and spills. (CAPR 4)

Procedure does not -See Training Failed Barrier-actions prompt radiological response NSP-RP-6101 50.75(g) does not Lack of knowledge of - Develop and implement Standard Exelon procedures to provide integrated and (FB-3) clearly address Title 35 IAC part 620 detailed spill and leak response requirements to ensure full compliance with state tritium groundwater quality and federal laws and regulations and integrate Exelon resources to respond to radiological leaks and spills. (CAPR 4)

-RP manager to present to peer group changes to 50.75(g) procedure to clearly address actions necessary for tritiated water spills, including evaluation for dose assessment to the public and initiate follow-up actions as appropriate to track necessary procedure changes. (CA-21)

-Review 50.75(g) files to ensure tritium and or any other isotopes are included for all blowdown vacuum breaker water events and perform 50.75(g) evaluation for all blowdown vacuum breakers not previously completed. (CA-30)

-See Training Failed Barrier actions 47

Attachment 2 Page 2 of 11 Barrier Analysis Failed or ineffective barrier How Barrier Failed Why Barrier Failed Corrective action to Restore Barrier to Effectiveness RP-AA No guidance for low Lack of knowledge of Develop and implement Standard Exelon procedures to provide integrated (FB-4) level spills Title 35 IAC part 620 and detailed spill and leak response requirements to ensure full compliance groundwater quality with state and federal laws and regulations and integrate Exelon resources to respond to radiological leaks and spills. (CAPR-4)

- See Training Failed Barrier actions WC-AA-106 WC called issues Lack of knowledge of - See Training Failed Barrier actions Attachment I implies a "C", not recognizing Title 35 IAC part 620 - Corporate Work Control to implement revision of WC-AA-106 to "B2" if increased that sampling for groundwater quality incorporate a higher work priority for response to low level radioactive water sampling tritium would be being released to the environment. (CA-26)

(FB-5) required BwOA No guidance for low Lack of knowledge of Develop and implement Standard Exelon procedures to provide integrated (Radiological spill level spills Title 35 IAC part 620 and detailed spill and leak response requirements to ensure full compliance procedure does not groundwater quality with state and federal laws and regulations and integrate Exelon resources to exist) respond to radiological leaks and spills. (CAPR-4)

(FB-6) - See Training Failed Barrier actions LS-AA-1020 & 1110 Does not reflect Lack of knowledge of -Corporate Regulatory Assurance to perform an extent of condition review Reportability Manual ODCM REMP/RETS Title 35 IAC part 620 regarding ODCM, REMP, RETS and state regulations for needed changes to (FB-7) reporting groundwater quality the Reportability Manual and create additional actions as required. (CA-1l) requirements -Corporate Regulatory Assurance to revise the Reportability Manual for reporting requirements of 35 IAC 611/620 Groundwater Tritium Release Path, 20,000 pCi/L limitations, and Illinois SB241 Community Right to Know requirements. (CA-12)

- See Training Failed Barrier actions 48

Attachment 2 Page 3 of 11 Barrier Analysis Failed or ineffective barrier How Barrier Failed Why Barrier Failed Corrective action to Restore Barrier to Effectiveness LS-AA-1020 & 1110 Does not reflect 35 Lack of knowledge of -Corporate Regulatory Assurance, to perform an extent of condition review Reportability Manual IAC 620 Title 35 IAC part 620 regarding ODCM, REMP, RETS and state regulations for needed changes to (FB-8) Groundwater Tritium groundwater quality the Reportability Manual and create additional actions as required. (CA- 11)

Release Path, 20,000 -Corporate Regulatory Assurance to revise the Reportability Manual for pCi/L limitations reporting requirements of 35 IAC 611/620 Groundwater Tritium Release Path, 20,000 pCi/L limitations, and Illinois SB241 Community Right to Know requirements. (CA-12)

- See Training Failed Barrier actions LS-AA-1020 & 1110. ENV 3.26 does not Lack of knowledge of -Corporate Regulatory Assurance to perform an extent of condition review Reportability Manual clearly warn of Title 35 IAC part 620 regarding ODCM, REMP, RETS and state regulations for needed changes to (FB-9) tritium groundwater groundwater quality the Reportability Manual and create additional actions as required. (CA-1 1) quality standards -Corporate Regulatory Assurance to revise the Reportability Manual for reporting requirements of 35 IAC 611/620 Groundwater Tritium Release Path, 20,000 pCi/L limitations, and Illinois SB241 Community Right to Know requirements. (CA-12)

- See Training Failed Barrier actions LS-AA-1020 & 1110 RAD 1.21, 10OCi Lack of knowledge of - See Training Failed Barrier actions Reportability Manual tritium 24h release tritium amounts released (FB-10) limitation not checked LS-AA-1020 & 1110 SAF 1.9 New Right No program for review Review the process by which the company becomes aware of new Reportability Manual to Know legislation and promulgation of new environmental laws and regulations for radiological and non-radiological (FB-11) not reflected, laws. issues and how they are integrated and communicated into company policies, programs, and procedures. Assign additional actions as necessary, if process changes are needed. (CA- 14) 49

Attachment 2 Page 4 of 11 Barrier Analysis Failed or ineffective barrier How Barrier Failed Why Barrier Failed Corrective action to Restore Barrier to Effectiveness ER-BR-400-101 No precaution for Lack of knowledge of -Develop and implement Standard Exelon procedures to provide integrated Engineering tritium groundwater Title 35 IAC part 620 and detailed spill and leak response requirements to ensure full compliance Walkdown PM concern groundwater quality with state and federal laws and regulations and integrate Exelon resources to Procedure respond to radiological leaks and spills.

(FB-12) (CAPR-4)

- See Training Failed Barrier actions OBwOS CW-A1 OPS No precaution for Lack of knowledge of Develop and implement Standard Exelon procedures to provide integrated Walkdown PM tritium groundwater Title 35 IAC part 620 and detailed spill and leak response requirements to ensure full compliance Procedure concern groundwater quality with state and federal laws and regulations and integrate Exelon resources to (FB-13) respond to radiological leaks and spills. (CAPR-4)

- See Training Failed Barrier actions EN-AA-Environmental No guidance for Lack of knowledge of -Develop and implement Standard Exelon procedures to provide integrated procedures radiological spills Title 35 IAC part 620 and detailed spill. and leak response requirements to ensure full compliance (FB-14) that can get to groundwater quality with state and federal laws and regulations and integrate Exelon resources to drinking water respond to radiological leaks and spills. (CAPR-4) supplies -See training failed actions barrier actions BwOP CW-12 No shutdown Lack of knowledge of - Ops to add precautions to BwOP CW-12, BwOP WX-526TI, & BwOP WX-(FB-15) precautions during a Title 35 IAC part 620 501TI for release shutdown on leak to environment and for the release release for a leak in groundwater quality restrictions dealing with Reportability Manual Section RAD 1.21 (i.e.: 100 the blowdown system Ci. limit on tritium releases over a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period). (CA-20)

-See training failed barrier actions BwOP WX-526TI, No shutdown Lack of knowledge of - Ops to add precautions to BwOP CW-12, BwOP WX-526TI, & BwOP WX-(FB-16) precautions during a Title 35 IAC part 620 501TI for release shutdown on leak to environment and for the release release for a leak in groundwater quality restrictions dealing with Reportability Manual Section RAD 1.21 (i.e.: 100 the blowdown system Ci. limit on tritium releases over a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period). (CA-20)

-See training failed barrier 50

Attachment 2 Page 5 of 11 Barrier Analysis Failed or ineffective barrier How Barrier Failed Why Barrier Failed Corrective action to Restore Barrier to Effectiveness BwOP WX-501TI No shutdown Lack of knowledge of Title 35 IAC part 620 - Ops to add precautions to BwOP CW- 12, BwOP WX-526TI, (FB-17) precautions during a groundwater quality & BwOP WX-501TI for release shutdown on leak to release for a leak in environment and for the release restrictions dealing with the blowdown system Reportability Manual Section RAD 1.21 (i.e.: 100 Ci. limit on tritium releases over a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period). (CA-20)

- See training failed barrier actions Alarms/ Other Issue Annunciators "a" Leak detection on Only performed Not often enough to detect leaks. System has Braidwood System Engineering to review operation of the CW vacuum breakers annually at the time inherent suspended materials in the CW, which lowdown system and determine the optimum monitoring scope (FB-18) of the 1998 event, can cause the valves to stick open, allowing nd frequency of inspection PM's and walk downs for the Recently performed tritiated water to be released. ,ystem. If applicable, identify gaps and create additional ATI's on semi-annual basis. s required (CA-22)

Currently (Since Sept. 2005) -Braidwood System Engineering to research and evaluate performed monthly passive vacuum breaker replacement options and present findings to PHC for approval if the CW Blowdown system will be used for radiological releases in the future (CA-23)

Alarms and Did not alarm Did not exist. Neither the Operations Department, System Engineering to work with Design Engineering to annunciators which is responsible for operating and monitoring research and evaluate viable remote monitoring (FB-19) the CW B/D System, nor Plant Engineering, which instrumentation systems that can detect lower level external has responsibility for managing the CW B/D leakage from the blowdown system and automatically notify System, recognized the need for, nor did they Braidwood Operations if the CW blowdown system will be pursue installation of a remote detection system used for radiological releases. (CA-24) for each vacuum breaker. Such a system may have allowed earlier detection and isolation of the leaks described in Table 1, which could have reduced environmental impact.

51

Attachment 2 Page 6of 11 Barrier Analysis

'Failed or ineffective barrier How Barrier Failed Why Barrier Failed Corrective action to Restore Barrier to Effectiveness Preventative CF-1 maintenance/

design configuration Piping/Valves Water hammer events Changed BwOP-CW12 BwOP CW-12 revised to mitigate water-hammer - revision 14.

equipment failures and created a water (Completed, 01/19/01) . Corrective actions reversed by a subsequent (FB-20) hammer issue revision.

Corrective actions to be addressed under IR 453381. (CA-31)

Inadequate R Lack of preventative Institute a Preventative Maintenance Program and system modifications, preventative maintenance program which are complete and have been verified to be effective in preventing maintenance for these valves major valve failures that result in large volume spills. (CAPR 1) programs and v Valves were not inadequate design designed to handle configuration the water hammer events Training CF-7 Certification of No training on a Did not know Title 35 Generate TR to analyze the chemistry management and technician level of Chemistry personnel response to a liquid IAC part 620 groundwater knowledge regarding the CW B/D system and the radioactivity expected to (FB-21) radiological spill for Tritium concentration be present. Refer to the Root Cause Report to be used as a case siudy.

requirements of Title limits (CA-18) 35 IAC part 620 groundwater quality.

52

Attachment 2 Page 7 of 11 Barrier Analysis Failed or ineffective barrier How Barrier Failed Why Barrier Failed Corrective action to Restore Barrier to Effectiveness Licensed and Non- No Environmental Did not know Title 35 Generate TR to analyze the operations personnel level of knowledge licensed Operator spill training for low IAC part 620 groundwater regarding the CW B/D system and the radioactivity expected to be present.

initial and level radioactive quality Refer to the Root Cause Report to be used as a case study. (CA-19) requalification training liquids (FB-22)

Certification of RP/HP Lack of cert guide for Did not know Title 35 Generate TR to analyze the RP management and technician level of (FB-23) low level radioactive IAC part 620 groundwater knowledge regarding the CW B/D system and the radioactivity expected to be liquid spills quality. - resent. Refer to the Root Cause Report to be used as a case study. (CA-17)

Regulations CF-5 ODCM requires Braidwood has Did not know Title 35 Evaluate the groundwater and food crop pathway per ODCM Table 12.5-1 evaluation of demonstrated a IAC part 620 groundwater Section 3.a note (6). Assign additional actions as necessary, if the pathway groundwater pathway if credible pathway tritium concentration is credible. (CA-15) credible limits (FB-24)

ODCM requires Braidwood has Did not know Title 35 Revise the Site specific portions of the ODCM to incorporate the new evaluation of demonstrated a LAC part 620 groundwater monitoring wells as determined by the ODCM Environmental Specialist to be groundwater pathway if credible pathway Tritium concentration credible groundwater (well water) monitoring sources into the ODCM Table credible limits 11-1 Section 3.a note (6) and ODCM REMP Table 12.5-1 Section 3a Note (FB-25) (6).groundwater. (CA-16)

Title 35 IAC part 611 ODCM does not Did not know Title 35 Review the process by which the company becomes aware of new groundwater quality reflect state IAC part 611 groundwater environmental laws and regulations for radiological and non-radiological (FB-26) groundwater quality issues and how they are integrated and communicated into company policies, requirements programs, and procedures. Assign additional actions as necessary, if process changes are needed. (CA-14) 53

Attachment 2 Page 8 of 11 Barrier Analysis Failed or ineffective barrier jHow Barrier Failed jWhy Barrier Failed Corrective action to Restore Barrier to Effectiveness Title 35 IAC part 620 ODCM does not Did not know Title 35 Revise the Midwest ODCM and/or program procedures to incorporate the groundwater quality reflect state IAC part 620 groundwater State of IL requirement of <20,000 pCi/L of tritium for groundwater (35 IAC (FB-27) groundwater quality standards. 620.410.e).3)) and the State of IL requirement for non-degradation (35 IAC requirements. 620.301.a)) (CA-5)

Revise the ODCM and/or program procedures as warranted to incorporate the State of PA requirements for radioactivity in groundwater. (CA-6)

Revise the ODCM and/or program procedures as warranted to incorporate the State of NJ requirements for radioactivity in groundwater (CA-7)

Clearly define to each station (extent of condition), the changes to the ODCM based on review of Illinois laws governing radioactive contamination of groundwater (potable water). Assign additional corrective actions to ensure site's ODCM reflects and implements applicable regulations. (CA-8)

Clearly define to each station (extent of condition), the changes to the ODCM based on review of Pennsylvania laws governing radioactive contamination of groundwater (potable water). Assign additional corrective actions to ensure site's ODCM reflects and implements applicable regulations. (CA-9)

Clearly define to each station (extent of condition), the changes to the ODCM based on review of New Jersey laws governing radioactive contamination of groundwater (potable water). Assign additional corrective actions to ensure site's ODCM reflects and implements applicable regulations. (CA-10)

Review the process by which the company becomes aware of new environmental laws and regulations for radiological and non-radiological issues and how they are integrated and communicated into company policies, programs, and procedures. Assign additional actions as necessary, if process changes are needed. (CA-14) 54

Attachment 2 Page 9 of 11 Barrier Analysis Failed or ineffective barrier .. How Barrier Failed Why Barrier Failed Corrective action to Restore Barrier to Effectiveness Corporate Oversight Did not uncover 2 Corporate audits did not Revise CY-AA- 170-000 and associated procedures to require audits of the CY-AA-170-000, missing State check program to ODCM against applicable laws and regulations at an acceptable frequency.

CY-AA-170-100, regulations or the sufficient detail Review the need for revision to include State regulations into Step 4.2.1 basis CY-AA-170-1000, state groundwater of the ODCM. Create additional actions as warranted. (CA- 13) tritium concentration CY-AA-170-200, issue.

CY-AA- 170-2000, CY-AA-170-2000, CY-AA-170-300, CY-AA-170-3100.

(FB-28)

Notification CF-6 NOS Audit NOSA- Did not uncover two NOS Audit Plan did not Discuss this RCR with the Corporate NOS Peer Group to evaluate changing BRW-05-08 (AR (2) missing state check program to the NOS auditing template standard for the ODCM Program. Document 2877 18) November 22, regulations or the sufficient detail, did not results and assign additional actions as required. (ACIT-28) 2005 state groundwater verify ODCM met (11-29) tritium concentration applicable state issue regulations Notice to other Site Did not always No procedure to assure Develop and implement Standard Exelon procedures to provide integrated Departments when an inform all affected consistent approach to and detailed spill and leak response requirements to ensure full compliance event occurred parties leaks/spills with state and federal laws and regulations and integrate Exelon resources to (FB-30) respond to radiological leaks and spills. (CAPR-4) 55

Attachment 2 Page 10 of 11 Barrier Analysis Failed or ineffective barrier How Barrier Failed Why Barrier Failed Corrective action to Restore Barrier to Effectiveness Notice to sites of new Sites not informed of Program not robust Review the process by which the company becomes aware of new State Regulations new Illinois SB241, environmental laws and regulations for radiological and non-radiological (FB-31) Community Right to issues and how they are integrated and communicated into company policies, Know programs, and procedures. Assign additional actions as necessary, if process changes are needed. (CA- 14)

Work Orders Other Issue Model PM work orders Failed to have RP Did not know Title 35 - RP to provide information to Work Planning so that a work standard can be and current work sampling of leaks and IAC part 620 groundwater created for work activities that involve potentially tritiated water. This orders for B/D vacuum how to properly quality information will be used to update PM model work orders and current work breakers dispose of liquids not orders involving potentially triiiated water. (CA-25)

(FB-32) in work order - Using the information provided by RP, create a work standard to be used for instructions. work activities that involve potentially tritiated water and update PM model work orders and current work orders involving potentially tritiated water (RWP, sample for tritium, instructions for pumping tritiated water). (CA-27) 56

Attachment 2 Page 11 of 11 Barrier Analysis Failed or ineffective barrier How Barrier Failed Why Barrier Failed Corrective action to Restore Barrier to Effectiveness Oversight CF-4 and CF-2 Weak management CF4: Braidwood Lack of questioning OP-AA-106-101-1002, Exelon Nuclear Issues Management, will be revised review and oversight of Senior Management attitude regarding to: 1) improve Corrective Action Program (CAP) controls of Issues spill response did not question the unplanned spills from the Management teams, 2) utilize the tools and techniques of the Exelon HU-AA-activities. radiological impact of blowdown system. 102 and HU-AA-1212, Technical Human Performance Practices and (FB-33) all leaks that had Technical Task Risk/Rigor Assessment, Pre-Job Brief, Independent Third happened. Party Review, and Post-Job Brief procedures, 3) strengthen reporting requirements to affected station Senior Management, and 4) define affected station Senior Management responsibilities for "cradle to grave" oversight and challenge of events and issues. (CAPR 5)

CF2: Lack of Did not know Title 35 The Braidwood Tritium Remediation Team will determine the methodology questioning attitude IAC part 620 groundwater and implement the plan for future radiological releases, including leakage for low level Tritium concentration standards. (CAPR 2) radiological spills. limits Develop a case study of this event. Provide initial and continuing training for The need for a near MRC/SOC members. (CA-2) zero leakage standard was not identified. Evaluate conducting Dynamic Learning Activity (DLA) on a Duty Team basis using 2000 release conditions and revised response and reporting procedures implemented in CAPR 4. Create additional assignments as warranted. (CA-3)

Review other potential leaks beyond tritium to address extent of condition regarding Exelon management's control of hazardous material spills. If deficiencies are noted, write IR's to have those deficiencies addressed.

(CA-4) 57

Attachment 3A

-Cause & Effect Analysis Effect Symptom Why Cause / Reason Vacuum breaker leaks Small 'leaks were never considered to occurred after 2000 be a problem Small leaks were never 2000 Root Cause Team only considered .to be a problem addressed major failures 2000 Root Cause Team 2000only adr sed TemajThe 2000 charter was to determine the only addressed major major failures failures

  • The charter was narrowly scoped due The 2000 charter was to to two teams were developed to determine the major failures perform the Root Cause and Radiological spill Response The charter was narrowly scoped due to two teams Was not considered a problem as were developed to perform small leaks did not leave the site the Root Cause and Radiological spill Response 58

Was not considered a problem as small leaks did People did not know the 1991 statute not leave the site for groundwater.

The need for a near zero leakage 1991lestatte for standard was not identified, due to a gr d watutefor. lack of Technical Rigor/Questioning groundwater. ÷Attitude (Root Cause 2).

The need for a near zero leakage standard was not identified, due to a lack of At this time the HU-AA-1212 and 102 Technical Rigor/ procedures did not exist.(CAPR 3)

Questioning Attitude (Root Cause 2).

59

Attachment 3B

-Cause & Effect Analysis Effect I Symptom Why Cause / Reason Tritium found off site Inadequate response Personnel not aware of the B/D water Tritium exceeding groundwater Inadequate response limits. Belief that release package authorized unrestricted release to environment.

Personnel not aware of the B/D water Tritium Personnel not aware of the IEPA exceeding limits. Belief that tritium limit requirements for release package authorized groundwater unrestricted release to environment.

Personnel not aware of the JEPA tritium limit Knowledge deficiency requirements for groundwater No integrated procedural guidance for Knowledge deficiency groundwater radiological spills (Root Cause 3) 60

Attachment 3C

-Cause & Effect Analysis Effect I Symptom Why Cause / Reason Tritium found off site Ineffective response in 2000 Ineffective response in Sampling not performed for tritium in 2000 groundwater Sampling not performed for Poor decision by Spill Team not to tritium in groundwater sample Poor decision by Spill Weak questioning attitude and Team not to sample inadequate challenge culture (Root Cause 4)

OP-AA-106-101-1002 (currently, OP-Weak questioning attitude AA-101-503 in year 2000) was not and inadequate challenge specific enough in regarding culture management reporting requirements

_(CAPR 5) 61 E&CF Chart

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o r~aeledT,-r)st EF33 kwt, mlak (

c on.t.j fks&*U 64

Attachment 5 Change Analysis (The Change Analysis tool was inadequate to use effectively and was therefore not utilized as an input to this root cause report.)

Factors That Interview Successful Failed Change? Causal Influence Questions Performance Performance Factor?

Performance Factors That Influence Interview Successful Failed Change? Causal Performance Questions Performance Performance Factor?

Factors That Interview Successful Failed Change? Causal Influence Questions Performance Performance Factor?

Performance 65

Attachment 6 Page 1 of 6 Circ Water Blowdown System BACKGROUND INFORMATION The primary function of the Circulating Water Blowdown System is to provide for lake turnover to prevent undesirable chemical buildup in the lake. The secondary function of the Circ Water Blowdown System is to provide dilution for liquid rad waste releases. (See Attachment 7 for map.)

The Circulating Water Blowdown System is designed to return Cooling Lake water back to the Kankakee River. Processed fluids from the Sewage Treatment System and the Radwaste Treatment Systems discharge directly into the Circulating Water Blowdown system, where dilution occurs prior to release to the Kankakee River. The Wastewater Treatment Plant and the De'mineralizer Regenerant Waste systems along with various strainer/filter backwashes are returned to the Cooling Lake and thus are indirectly returned to the Kankakee River through the Blowdown line after dilution by the Cooling Lake.

The Circ Water Blowdown system begins at the Circ Water System supply piping to the condenser. Two 24" carbon steel pipes tap off the Circulating Water supply piping (one from each unit) and combine into-a 36" common header. A motor operated isolation valve (1/2CW018) is provided on each 24" line. The 6" Radwaste Treatment System discharge pipe connects to the 36" blowdown header. Downstream of the radwaste connection, the blowdown pipe is expanded to 48" prior to connection to the 3" Sewage Treatment Plant discharge pipe.

The 48" diameter blowdown pipe is reinforced concrete pipe (RCP) and runs along owner-controlled property until reaching the Blowdown structure at the Kankakee River. Eleven vacuum breaker assemblies are incorporated at the high points along the 48" diameter RCP to prevent pipe implosion when the blowdown system is shut off. The 48" RCP is split and reduced to two 24" discharge pipes at the Kankakee River blowdown structure. Each 24" discharge pipe was originally equipped with a motor operated spray valve. The entire piping network is approximately 29,000 ft long and was originally operated at about 12,000 gpm (-2.5 ft/s).

The Circ Water Blowdown system was originally designed to be maintained full of water and pressurized. This was accomplished through manipulation of the Blowdown Spray Valves, at the Kankakee River blowdown structure. These valves were susceptible to freezing due to their location and system operation requirements. Based on this, other maintenance issues, and parts obsolescence, these valves were eventually abandoned in the full open position in the late 66

Attachment 6 Page 2 of 6 1980's-. To allow-air release from the piping on start-up and to allow air introduction to protect against vacuum damage to the piping, vacuum breakers are installed.

'VA EMA9

  • 0j" N i.9 I NOTE: Above is typical. Braidwood has 48" reinforced concrete pipe. Other differences may apply.

System control was transferred to the upstream motor operator isolation valves located in the turbine building. This modification caused the blowdown line to operate in a partially voided condition in various locations, depending on elevation which allowed column separation water hammer events to occur when flow rates were changed significantly, i.e.; during system start-up or shut down.

Events were not initially seen because blowdown was essentially in service all the time. As a result of this change in operational methodology, the blowdown system would no longer be maintained full and pressurized upon shutdown.

Minimal technical review was performed on the hydraulic transient effects on the vacuum breakers from this method of operation.

67

Attachment 6 Page 3 of 6 A more rigorous technical review may have initiated the installation of surge protected check valves (which eventually occurred in 2001) before the majority of the leaks described in this report occurred. This is a missed opportunity.

In 1997, the Chemical Feed System was relocated from the Turbine Building to the Lake Screen House under modification M20-0-95-003. One of the primary reasons for centralization of the Chemical Feed system to the Lake Screen House was to reduce maintenance cost. This design change necessitated isolating the Circ Water Blowdown System on a daily basis to accommodate biocide injections into the Circ Water System, because our permits do not authorize discharge of biocide to the Kankakee River. When both units were in operation this was not an issue because partial blowdown flow was maintained from the unit not being chlorinated. The problem became apparent during outages when one unit was shut down. In this configuration, blowdown flow was stopped and started whenever the operating unit was chlorinated.

The daily requirement to isolate Circulating Water Blowdown for biocide injection, prompted the Operations Department to challenge the BwOP CW-12 procedural requirement to slowly open the motor operated valves for system start-up.

BwOP CW-12 was revised to allow fast motorized operation of motor operated valves, in lieu of slower manual throttling following short periods of system shutdown (i.e.: biocide injections).

68

Attachment 6 Page 4 of 6 Typical vacuum breaker:

AI R. RE LEASE VALVIE Ah%11 B lITTERLY VALVE 10 IFVI0 h4AL-CSIEE C"P34AW.V~ EWW)V:

~*~Efl.ata I.S.O MI.SScMJCWSC.,r Work history on the Circulating Water Blowdown System vacuum breakers was reviewed. There were no recorded vacuum breaker float assembly failures prior to 2000, however several instances of leaking air release valves were noted from the review. The VB-3 air release valve was discovered leaking in 12/98. PIF #

A1998-04324 was generated to address the flooding of site property and the Smiley Road ditch immediately adjacent to site property. The piping to the air release valve on the VB-1 failed in 12/96. The complete vacuum breaker assembly including air release valve was replaced with a new assembly in 1997.

It should be noted that the VB-1 vacuum breaker failed again on 11/20/2000. The float assembly broke at the bowl to guide bar weld. No other significant work history was identified.

The failure of the VB-2 float assembly was discussed with the vendor. Based on the failure description, the vendor indicated that it appeared to be consistent with the effects of a pressure surge (i.e. water hammer). The vendor indicated that surge protection check valves should be considered for a vacuum breaker when pipe flows exceed 6 ft/s and are required when flow velocities exceed 10 ft/s.

The vendor also recommended a 7-10 year PM frequency to address valve elastomer degradation. The condition was addressed by revising the operating procedure BwOP CW-12 to manually open and close the valves to slowly initiate or terminate blowdown flow.

69

Attachment 6 Page 5 of 6 The present circulating water blowdown system operates as follows. On system startup, the air/vacuum valve exhausts large amounts of air from the piping system until the float assembly in the air/vacuum valve rises with water level to close and seal during normal system operation.. To prevent the inrushing water from causing damage to the air/vacuum valve float, a surge check valve is installed just underneath the air/vacuum valve. The surge check is a spring loaded, normally open valve, which passes air through unrestricted. When water rushes into the check valve, the disc begins to close against the spring tension and reduces the flow rate of water into the air/vacuum valve by means of throttling holes in the disc. This ensures gentle closing of the air/vacuum valve float, regardless of initial flow velocity into the valve and minimizes pressure surges. Upon system shutdown, the vacuum valve is designed to open as water level decreases. The air release valve provides two functions. The primary function is to release small amounts of entrained air that accumulates at the high points during normal system operation. If not removed, this air that would increase head loss and reduce process flow. The air release valve also facilitates earlier opening of the main air/vacuum valve on system shutdown. On shutdowns, air pockets that develop at high points may be at positive pressure, tending to hold the main air/vacuum float on its seat even though water level is below the float assembly. However, the air release valve will vent the air and allow the main air/vacuum valve to open as soon as water level drops. Each vacuum breaker is provided with a butterfly isolation valve to facilitate vacuum breaker maintenance.

Modification of 2001-2003 changed the design of the air / vacuum valve assembly to a slow closing design with the use of a surge protector valve in-line.

This modification protects the air/vacuum valves from pressure surges experienced during water hammer events.

Modification of 2003 installed CW Blowdown Booster Pumps to increase the blowdown flow rate to 25,000 gpm for improving lake chemistry. With increased flow rates during booster pump operation the volume of voided blowdown line may decrease, closing previously open air / vacuum valves under lower flow conditions. Start up and shut down procedures for the booster pumps specify flow / pump increase / decrease ramp rates to minimize potential column separation water hammer pressure surges.

70

Attachment 6 Page 6 of 6 Modification of 2005 installed a de-chlorination modification to allow continuous operation of the Blowdown System while performing unit chlorination. This modification allowed blowdown to be in-service essentially all the time, reducing the potential for air / vacuum valves leaks caused by system flow rate changes.

The aggregate impact of the three modifications was to assure nearly continuous operation of the blowdown system which minimizes the inclusion of air and the possibility of damaging water hammer at the vacuum breaker valves.

71

Page lof 3 Attachment 7 Tritium Plume Maps F

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NTnrth Godley Braidwood Illinois Station Kankakee River 75

Attachment 8 Review of Exelon Hazmat Spill Response Procedures Page 1 of 3 In general, there is no spill response procedure, which would acknowledge the subsurface water transport mechanism from onsite to offsite locations. The three documents reviewed were a draft procedure circulated in 10/16/90, "General Action Plan for Response to Unmonitored Releases and Very Low Level Radioactive Spills", BwAP 750-4, "Hazardous Material Spill Response", and BwAP 1100-16, "Fire/Hazardous Materials Spill and/or Injury Response", and NSP-RP-6101, "10 CFR 50.75(g)(1) Documentation Requirements".

The most significant barrier deficiencies noted was that the 1990 draft procedure may have prompted reviewing hydrology and dose to the public from radiological contamination of groundwater. Additionally, the procedure to document the spill for 10 CFR 50.75(g)(1) requirements for decommissioning prompts to perform a potential dose impact to the public from the spill, but does not require any specific pathway (i.e. subsurface migration of contaminants to drinking water).

Procedure Relevant Content Barrier Analysis Draft Procedure CSG-001, The draft procedure contained pertinent information about: Missed opportunity to "General Action Plan for

  • For situations involving subsurface contamination, erect a barrier.

Response to Unmonitored corrective action may mean the preparation of a Releases and Very Low Level submittal pursuant to the I1Adm. Code 340.3020 and 10 This procedure may have Radioactive Spills" CFR 20.302 requesting the in-place disposal of prompted recognition of subsurface contamination, dose impacts from the Circulated as a Draft

  • Environment - refers to any surface water, groundwater, contamination of procedure 10/16/90. No sanitary or storm sewers, soil, land surface, or subsurface groundwater and record of this becoming an strata and vegetation, supporting hydrology actual procedure.
  • Subsurface contamination and hydrology 'concerns issues.

0 Reviewing to ensure the spill is not in excess of This procedure contains Reportable Quantity quantities in 40 CFR 302 App B or May have provided an information relevant to the 40 CFR 355 App A opportunity for all former underground water dose 0 Required evaluation of exposure pathways from CornEd nuclear plants to pathway to the public now infiltration and contamination of groundwater. recognize the potential being evaluated. Not issue.

implementing this procedure was a missed opportunity to erect a barrier to recognize Page 2 of 3 BwAP 750-4, "Hazardous In general, site personnel would not consider entry into the Minor missed barrier.

Material Spill Response" hazmat spill procedure for a water spill.

The procedure contains the following pertinent information: Missing this barrier was

  • The procedure references Hazardous Materials as listed in of no consequence. The 40 CFR 302.4, which lists many chemicals, but not RP organization did not 76

Procedure Relevant Content Barrier Analysis radioactive material. The intent of this reference is to have subsequent ensure that a "Reportable Quantity" has not been spilled proceduresto respond to on the ground. The absence of radioactive materials the subsurface transport from the list in the procedure does not preclude someone issues, which are of issue from looking for radioactive material in 40 CFR 302.4, today.

but the procedure does not offer a clear barrier to trip recognition of a radioactive material spill as a hazmat event per this procedure. Even if radioactive materials was clearly on the Reportable Quantity list, the RP organization does not have a procedure documenting additional required actions.

The procedure states, "Spills containing radiologically contaminated material shall be reported to the Radiation Protection Dept.

BwAP 1100-16, The hazmat procedure does not contain information to specify Minor missed barrier.

"Fire/Hazardous Materials actions that might direct specific radiological actions to minimize Spill and/or Injury Response" the significance of a similar event. The procedure essentially Missing this barrier was defers radiological spills to the RP organization. The procedure of no consequence. The contains the following radiological information: RP organization did not Notify Rad Protection to dispatch personnel to the have subsequent fire/spill area for radiation detection and first aid procedures to respond to purposes. the subsurface transport issues, which are of issue today.

Page 3 of 3 NSP-RP-6 101, "10 CFR This procedure is intended to provide the following information Missed barrier 50.75(g)(1) Documentation as required from the regulation:

Requirements"

  • 10 CFR 50.75(g)(1) Records of spills or other unusual The procedure requires an occurrences involving the spread of contamination in assessment of potential and around the facility, equipment, or site. These records dose to the public from may be limited to instances when significant the remaining radioactive contamination remains after any cleanup procedures or material, but does not when there is reasonable likelihood that contaminants prompt for the pathway of may have spread to inaccessible areas as in the case of subsurface migration possible seepage into porous materials such as concrete. through groundwater to These records must include any known information on drinking water.

identification of involved nuclides, quantities, forms, and concentrations.

  • The actual procedure requires addressing:

o Concentrations of involved radionuclides o Quantities of material(s) o Forms of material(s), (e.g. solubility and permeability of the contaminant) o Description of the event o Impact of the remaining radioactive material on the health and safety of the public o Affected areas

  • The procedure prompts to perform a potential dose impact to members of the public, but it does not describe pathways to be analyzed (i.e. subsurface migration of contaminants to drinking water). The general absence of tools to calculate the specifics of subsurface transport mechanisms may have prompted actual measurements through the drilling of wells to sample water or sample existing offsite wells. Corrective Action (CA-2 1) addresses performing a dose assessment to determine the dose impact to the public from radiological spills by including this action in the 10 CFR 50.75(g)(1) procedure. The purpose of corrective action 21 is to link 77

Procedure Relevant Content Barrier Analysis the 10CFR 50.75(g) with the ODCM for tracking the impact on dose of isotopics in groundwater.

78

Attachment 9 Reportability Manual Review - LS-AA-1 020 and LS-AA-1 110 Page 1 of 3 Various documents were reviewed by this Root Cause Investigation Team to determine the expected reporting requirements for an event such as discovering radiologically contaminated water leaking from a plant system onto the ground within the owner-controlled area.

LS-AA-1020 Radiological Decision Tree was reviewed. The Liquid Release or Spill portion of the tree references SAF 1.9, News Release or Notification of Other Government Agency. SAF 1.9 requires NRC notification for any event related to the health and safety of the public or onsite personnel, or protection of the environment requiring a news release or notification of another government agency. One example described is the unplanned release of radioactively contaminated materials. Since the vacuum breaker leaks (spills) were contained onsite, the leak would not be characterized as a release per the Offsite Dose Calculation Manual.

Since the leak was onsite, there was no perceived health or safety risk to the public. A review of several Incident Reports (IR's) indicates that these leaks were not considered a public risk since the leaks were onsite. These IR's also reasonably concluded that National Pollution Discharge Elimination System (NPDES) violations did not occur and therefore, Environmental Protection Agency (EPA) notification was not required. Based on the nature of the leak, there was no safety or health risk to onsite personnel. Therefore, it was reasonable to conclude that these events were not reportable per SAF 1.9.

The Liquid Release or Spill portion of the Radiological Decision Tree also references RAD 1.1, Events Involving Byproduct, Source or Special Nuclear Material that Cause or Threaten to Cause Significant Exposure or Release. One of the reporting requirements concerns the release of radioactive material inside or outside the restricted area, but is not reportable if the location is not normally stationed during routine operations. Since personnel would not normally be stationed at the vacuum breakers, reporting was not required.

RAD 1.4, Liquid Effluent Release requires reporting when radioactive material is present at levels greater than 10 times applicable limits. The piping leaks were within the restricted areas and therefore were not considered an effluent release. Migration of contaminated groundwater offsite should be considered an effluent release, but was not considered. To date, measurable tritium concentrations in groundwater offsite are within 10 times the applicable limits. The event is not reportable per RAD 1.4.

RAD 1.8, Effluent Release was not considered applicable since a release normally occurs at the authorized or intended discharge point. Therefore, reportability per RAD 1.8 was not considered. Offsite release via groundwater was not considered. Based on the measured tritium results off site, the requirements described in RAD .1.8 have not been exceeded and therefore, reportability per RAD 1.8 is not required.

79

Attachment 9.

Reportability Manual Review - LS-AA-1 020 and LS-AA-1110 Page 2 of 3 RAD 1.21, Release of Radionuclides, requires reporting when the limits of 40 CFR 302 are-exceeded. For tritium, the 40 CFR 302 limit is 100 Curies released within a 24-hour period.

Review of effluent release data indicates that the 100-curie limit was not challenged during radioactive releases over the vacuum breaker leakage timeframe. Therefore, reportability per RAD 1.21 was not required.

RAD 1.22, Release of Hazardous Substances-(including radionuclides) is not applicable based on the RAD 1.21 discussion.

The other sections of the Liquid Release or Spill portion of the Radiological Decision Tree do not apply.

The other sections of the Radiological Decision Tree were reviewed and do not apply.

LS-AA-1020 Environmental decision tree was also reviewed. The Other Significant Event section was reviewed. ENV 3.26 Unusual or Important Environmental Events requires reporting of any event that did or could have significant environmental impact. It is reasonable that a blowdown water spill onsite would not have a significant environmental impact and therefore notification would not be made. However, potential groundwater contamination and migration to public wells was not considered.

The other sections of the Environmental Decision Tree were reviewed and would not apply.

40 CFR 141.16 states that the average annual tritium concentration shall not exceed 20,000 pCi/L in a community drinking water system. A community drinking water system is defined in the regulation as a public water system that serves at least 15 year round residents. The reportability manual appropriately references 40 CFR 141.

35 IAC 620 has the same 20,000 pCi/L limit and definition of community drinking water system as described in 40 CFR 141.16. However, 35 IAC 620 does not limit the tritium concentration to community drinking water. This Illinois standard limits tritium concentration in "Class I: Potable Resource Water," which is defined, in part, as water located 10 feet or more below the surface that is capable of potable use. Per discussion with Conestoga-Rovers & Associates and the Exelon Hydrologist, onsite groundwater at Braidwood station is classified as Class I: Potable Resource Water in accordance with 35 IAC 620. Therefore, any tritium leakage into the groundwater onsite could exceed the requirements of 35 IAC 620.

The reporting requirements for the Radiological Environmental Monitoring Program (REMP) are specified in the Braidwood ODCM, section 12.5.1. Table 12.5-2 lists REMP reporting levels for tritium and other radionuclides that are monitored in various types of samples obtained. These ODCM required reporting requirements are not listed in the Reportability Manual. Groundwater samples indicate that the reporting level of tritium per Table 12.5-2 have been exceeded.

80

Attachment 9 Reportability Manual Review- LS-AA-1020 and LS-AA-1110 Page 3 of 3 The Braidwood ODCM REMP drinking water tritium concentration reporting requirements are consistent with the requirements of 40 CFR 141 and 35 IAC 620. However, per ODCM Section 12.5.1, reportability is based on a quarterly average. 40 CFR 141 and 35 IAC 620 reportability are based on an annual average - the ODCM reportability is conservative and consistent with the recommendations in NUREG 1301 Section 3.12.1.

There is no mention of 35 IAC 611 or 35 IAC 620 requirements in the Braidwood ODCM (CA4).

The Reportability Manual was reviewed for references to the various drinking water and groundwater standards. There is appropriate reference to 40 CFR 141 and 35 IAC 611.

However, there were not sufficient references to 35 IAC 620. Based on this review, there was inadequate knowledge of the requirements of 35 IAC 620 and the transport of radioactivity offsite via the groundwater pathway.

In 2005, Illinois passed SB241, which became effective on July 25, 2005. This legislation states that if the Illinois Environmental Protection Agency (IEPA) makes a determination that groundwater poses a threat of exposure above Class I groundwater standards (35 IAC 620),

then public notification is required. The IEPA does not require conclusive evidence of exceeding a standard. The notification can be based on modeling that demonstrates a trend towards exceeding a standard.

While this legislation does not require site reporting and does not change daily operation, it does impact the site because public notification can be made based on groundwater contaminant concentrations that are below reportable thresholds. There is no mechanism in place for site technical expertise to be made aware of new legislation such as Illinois SB241 (CA8).

References Braidwood Offsite Dose Calculation Manual LS-AA-1020, Reportability Reference Manual, Revision 8 LS-AA-1 110, Reportable Event SAF, Revision 6 LS-AA-1 120, Reportable Event Radiation (RAD), Revision 3 LS-MW-1 310, Reportable Event SAF, Revision 3 LS-MW-1 340, Reportable Event, ENV, Revision 4 LS-AA-1400, Event Reporting Guidelines, Revision 2 LS-MW-1340, Reportable Events, ENV, Revision 4 40 CFR 302, Designation, Reportable Quantities, and Notification 40 CFR 141, National Primary Drinking Water Regulations 35 IAC 611, Primary Drinking Water Standards 35 IAC 620, Groundwater Quality 81

Attachment 10 Page 1 of 14 Summary of Applicable State, Federal, and Offsite Dose Calculation Manual (ODCM) Regulations and Requirements for Tritium Releases to the Environment TITLE 35: ENVIRONMENTAL PROTECTION SUBTITLE F: PUBLIC WATER SUPPLIES CHAPTER I: POLLUTION CONTROL BOARD PART 620.410 GROUNDWATER QUALITY Effective November 25, 1991Class I: Potable Groundwater e) Beta Particle and Photon Radioactivity

1) Except due to natural causes, the average annual concentration of beta particle and photon radioactivity from man-made radionuclides shall not exceed a dose equivalent to the total body organ greater than 4 norem/year in Class I groundwater. If two or more radionuclides are present, the sum of their dose equivalent to the total body, or to any internal organ shall not exceed 4 mrem/year in Class I groundwater except due to natural causes.
2) Except for the radionuclides listed in subsection (e)(3), the concentration of man-made radionuclides causing 4 mrem total body or organ dose equivalent must be calculated on the basis of a 2 liter per day drinking water intake using the 168-hour data in accordance with the procedure set forth in NCRP Report Number 22, incorporated by reference in Section 620.125(a).
3) Except due to natural causes, the average annual concentration assumed to produce a total body or organ dose of 4 mrem/year of the following chemical constituents shall not be exceeded in Class I groundwater:

Critical Standard Constituent Organ (pCi/L)

Tritium Total body 20,000.0 Strontium-90 Bone marrow 8.0 82

Attachment 10 Page 2 of 14 ODCM Appendix A Revision 3 January 2002 A.2.2 Liquid Effluent Concentrations Requirement Requirement One method of demonstrating compliance to the requirements of 10 CFR 20.1301 is to demonstrate that the annual average concentrations of radioactive material released in gaseous and liquid effluents do not exceed the values specified in 10 CFR 20 Appendix B, Table 2, Column 2. (See 10 CFR 20.1302(b)(2).)

However, as noted in Section A.5.1, this mode of 10 CFR 20.1301 compliance has not been elected.

[Mode of compliance selected is as follows:]

As a means of assuring that annual concentration limits will not be exceeded, and as a matter of policy assuring that doses by the liquid pathway will be ALARA; RETS provides the following restriction:

"The concentration of radioactive material released in liquid effluents to unrestricted areas shall be limited to ten times the concentration values in Appendix B, Table 2, Column 2 to 10 CFR 20.1001-20.2402."

This also meets the requirement of Station Technical Specifications and RETS.

A.2.4 Tank Overflow Requirement To limit the consequences of tank overflow, the RETS/Technical Specifications may limit the quantity of radioactivity that may be stored in unprotected outdoor tanks. Unprotected tanks are tanks that are not surrounded by liners, dikes, or walls capable of holding the tank contents and that do not have tank overflows and surrounding area drains connected to the liquid radwaste treatment system. The specific objective is to provide assurance that in the event of an uncontrolled release of a tank's contents, the resulting radioactivity concentrations beyond the unrestricted area boundary, at the nearest potable water supply and at the nearest surface water supply, will be less than the limits of 10 CFR 20 Appendix B, Table 2; Column 2.

The Technical Specifications and RETS may contain a somewhat similar provision. For most nuclear power stations, specific numerical limits are specified on the number of curies allowed in affected tanks.

83

Attachment 10 Page 3 of 14 A.2.5 Operability and Use of the Liquid Radwaste Treatment System Requirement The design objectives of 10 CFR 50, Appendix I and RETS/Technical Specifications require that the liquid radwaste treatment system be operable and that appropriate portions be used to reduce releases of radioactivity when projected doses due to the liquid effluent from each reactor unit to restricted area boundaries exceed either of the following (see Section 12.3 of each station's RETS or Technical Specifications);

  • 0.06 mrem to the total body in a 31 day period.
  • 0.2 mrem to any organ in a 31 day period.

A.2.6 Drinking Water Five nuclear power stations (Braidwood, Dresden, LaSalle, Quad Cities, and Zion) have requirements for calculation of drinking water dose that are related to 40 CFR 141, the Environmental Protection Agency National Primary Drinking Water Regulations. These are discussed in Section A.6.

A.6 DOSE DUE TO DRINKING WATER (40 CFR 141)

The National Primary Drinking Water Regulations, 40 CFR 141, contain the requirements of the Environmental Protection Agency applicable to public water systems. Included are limits on radioactivity concentration. Although these regulations are directed at the owners and operators of public water systems, several stations have requirements in their Technical Specifications related to 40 CFR 141.

A.6.1 40 CFR 141 Restrictions on Manmade Radionuclides Section 141.16 states the following (not verbatim):

(a) The average annual concentration of beta particle and photon radioactivity from man-made radionuclides in drinking water shall not produce an annual dose equivalent to the total body or any internal organ greater than 4 millirem/year.

(b) Except for the radionuclides listed in Table A-0, the concentration of man-made radionuclides causing 4 mrem total body or organ dose equivalents shall be calculated on the basis of drinking 2 liter of water per day. (Using the 168 hour0.00194 days <br />0.0467 hours <br />2.777778e-4 weeks <br />6.3924e-5 months <br /> data listed in "Maximum Permissible Body Burdens and Maximum Permissible Concentration of Radionuclides in Air or Water for Occupational Exposure, "NBS Handbook 69 as amended August 1963, U.S. Department of Commerce.). If two or more radionuclides are present, the sum of their annual dose equivalents to the total body or any organ shall not exceed 4 milliremlyear.

84

Attachment 10 Page 4 of 14 TABLE A-0 AVERAGE ANNUAL CONCENTRATIONS ASSUMED TO PRODUCE A TOTAL BODY OR ORGAN DOSE OF 4 MREM/YR Radionuclide Critical Organ pCi / liter Tritium Total body 20,000 Strontium-90 Bone marrow 8 LIQUID EFFLUENTS Chapter 12 Revision 7 September, 2002 12.3.1 Concentration Operability Requirements 12.3.1.A The concentration of radioactive material released in liquid effluents to UNRESTRICTED AREAS (see Braidwood Station ODCM Annex, Appendix F, Figure F-i) shall be limited to 10 times the concentration values in Appendix B, Table 2, Column 2 to 10 CFR 20.1001-20.2402, for radionuclides other than dissolved or entrained noble gases. For dissolved or entrained noble gases, the concentration shall be limited to 2x10-4 microCurie/mI total activity.

Applicability: At all times Action:

1t With the concentration of radioactive material released in liquid effluents to UNRESTRICTED AREAS exceeding the above limits, immediately restore the concentration to within the above limits.

Surveillance Requirements 12.3.1.B.1 Radioactive liquid wastes shall be sampled and analyzed according to the sampling and analysis program of Table 12.3-1.

12.3.1.B.2 The results of the radioactivity analysis shall be used in accordance with the methodology and parameters in the ODCM to assure that the concentrations at the point of release are maintained within the limits of 12.3.1.A.

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Attachment 10 Page 5 of 14 Bases 12.3.1.C This section is provided to ensure that the-concentration of radioactive materials released in liquid waste effluents to UNRESTRICTED AREAS will be less than 10 times the concentration values in Appendix B, Table 2, Column 2 to 10 CFR 20.1001-20.2402. This limitation provides additional assurance that the levels of radioactive materials in bodies of water in UNRESTRICTED AREAS will result in exposures within: (1) the Section II.A design objectives of Appendix 1,10 CFR 50, to a MEMBER OF THE PUBLIC, and (2) the limits of 10 CFR 20.1301.

This section applies to the release of radioactive materials in liquid effluents from all units at the site.

The required detection capabilities for radioactive materials in liquid waste samples are tabulated in terms of the lower limits of detection (LLDs). Detailed discussion of the LLD, and other detection limits can be found in HASL Procedures Manual, HASL-300 (revised annually), Currie, L.A., "Limits for Qualitative Detection and Quantitative Determination -

Application to Radiochemistry," Anal. Chem. 40, 586-93 (1968), and Hartwell, J.K.,

"Detection Limits for Radioana!ytical Counting Techniques," Atlantic Richfield Hanford Company Report ARH-SA-21 5 (June 1975).

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Attachment 10 Page 6 of 14 TABLE 12.3-1 RADIOACTIVE LIQUID WASTE SAMPLING AND ANALYSIS PROGRAM LIQUID RELEASE SAMPLING MINIMUM ANALYSIS TYPE OF ACTIVITY LOWER, LIMIT OF TYPE FREQUENCY FREQUENCY ANALYSIS DETECTION (LLD)(')

(PiCVmI)

I. Batch Release P P Principal Gamma Emitters(7) 5x10-7 Tanks(2) Each Batch Each Batch 1-131 1xi 0. 6 P M Dissolved and Entrained 1x10"5 One Batch/M Gases (Gamma Emitters)

P M H-3 1xi 0 5 Each Batch Composite (3) 7 Gross Alpha 1x1 0-P Q Sr-89, Sr-90 5x1 0-8 Each Batch Composite (3)

Fe-55 lxi 06 7

2. Continuous W Principal Gamma Emitters(7) 5x1 0 Releases (4) Continuous(s) Composite(5) 1-131 1x10s6
a. Circulating Water M M Dissolved and Entrained lx10 5 Blowdown Grab Sample Gases (Gamma Emitters) 5
b. Waste Water M H-3 1x10*

Treatment Continuous(5) Coin posite(5 )

Discharge to Circulating Water Discharge 7

Gross Alpha 1x1 0

c. Condensate Continuous(5 ) Q 5 Sr-89, Sr-90 5x1 0.8 Polisher Sump Composite( )

Discharge 6

Fe-55 1x10 87

Attachment 10 Page 7 of 14 TABLE 12.3-1 (Continued)

RADIOACTIVE LIQUID WASTE SAMPLING AND ANALYSIS PROGRAM LIQUID RELEASE SAMPLING MINIMUM ANALYSIS TYPE OF ACTIVITY LOWER LIMIT OF TYPE FREQUENCY FREQUENCY ANALYSIS DETECTION (LLD)(1)(PCi/mI)

3. Continuous W(6) W(6) Principal Gamma 5x10-7 Release(4) Grab Emitters(7)

Essential Sample Service Water Reactor Containment Fan Cooler (RCFC) Outlet Line 1-131 x10"6 H-3 lx10-5 M (6) Dissolved and 1x10.5 Entrained Gases (Gamma Emitters)

4. Continuous None None Principal Gamma 5x10-7 Surge Tank Emitters(7)

Vent-Component Cooling Water Line (8)

Dissolved and I xl0 5 Entrained Gases (Gamma Emitters) 1-131 1xl 0-6 88

Attachment 10 Page 8 of 14 TABLE 12.3-1 (Continued)

RADIOACTIVE LIQUID WASTE SAMPLING AND ANALYSIS PROGRAM TABLE NOTATIONS (1) The LLD is defined, for purposes of these sections, as the smallest concentration of radioactive material in a sample that will yield a net count, above system background, that will be detected with 95% probability with only 5% probability of falsely concluding that a blank observation represents a "real" signal.

For a particular measurement system, which may include radiochemical separations:

LLD = 4.66sh E x V x 2.22 x10 6 x Y x exp (-XAt)

Where:

LLD = the lower limit of detection (microCuries per unit mass or volume),

Sb = the standard deviation of the background counting rate or of the counting rate of a blank sample as appropriate (counts per minute),

E = the counting efficiency (counts per disintegration),

V = the sample size (units of mass or volume),

2.22 X1i06 = the number of disintegrations per minute per microCurie, Y = the fractional radiochemical yield, when applicable, k = the radioactive decay constant for the particular radionuclide (sec .), and At = the elapsed time between the midpoint of sample collection and the time of counting (sec).

Typical values of E, V, Y, and At should be used in the calculation.

Alternative LLD Methodology An alternative methodology for LLD determination follows and is similar to the above LLD equation:

LLD = (2.71 + 4.654/B) x Decay E x q x b x Y x t (2.22 X10 6 )

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Attachment 10 Page 9 of 14 TABLE 12.3-1 (Continued)

RADIOACTIVE LIQUID WASTE SAMPLING AND ANALYSIS PROGRAM TABLE NOTATIONS Where:

B = background sum (counts)

E = counting efficiency, (counts detected/disintegration's) q = sample quantity, (mass or volume) b = abundance, (if applicable)

Y = fractional radiochemical yield or collection efficiency, (if applicable) t = count time (minutes) 2.22X106 = number of disintegration's per minute per microCurie 2.71 + 4.65B= k2 + (2k q/2 q B), and k = 1.645.

(k=value of the t statistic from the single-tailed t distribution at a significance level of 0.95 and infinite degrees of freedom. This means that the LLD result represents a 95% detection probability with a 5% probability of falsely concluding that the nuclide present when it is not or that the nuclide is not present when it is.)

Decay = eýt [XRT/(1 -eXRm)] [XT,(1 -e'Td)], (if applicable)

X = radioactive decay constant, (units consistent with At, RT and Td)

At = "delta t', or the elapsed time between sample collection or the midpoint of sample collection and the time the count is started, depending on the type of sample, (units consistent with X)

RT= elapsed real time, or the duration of the sample count, (units consistent with k)

Td = sample deposition time, or the duration of analyte collection onto the sample media',

(units consistent with X)

The LLD may be determined using installed radioanalytical software, if available. In addition to determining the correct number of channels over which to total the background sum, utilizing the software's ability to perform decay corrections (i.e. during sample collection, from sample collection to start of analysis and during counting), this alternate method will result in a more accurate determination of the LLD.

90

Attachment 10 Page 10 of 14 It should be recognized that the LLD is defined as a before the fact limit representing the capability of a measurement system and not as an after the fact limit for a particular measurement.

TABLE 12.3-1 (Continued)

RADIOACTIVE LIQUID WASTE SAMPLING AND ANALYSIS PROGRAM TABLE NOTATIONS (2) A batch release is the discharge of liquid wastes of a discrete volume. Prior to sampling for analyses, each batch shall be isolated, and then thoroughly mixed to assure representative sampling.

(3) A composite sample is one in which the quantity of liquid sampled is proportional to the quantity of liquid waste discharged and in which the method of sampling employed results in a specimen that is representative of the liquids released.

(4) A continuous release is the discharge of liquid wastes of a nondiscrete volume, e.g., from a volume of a system that has an input flow during the continuous release.

(5) To be representative of the quantities and concentrations of radioactive materials in liquid effluents, samples shall be collected continuously whenever the effluent stream is flowing. Prior to analyses, all samples taken for the composite shall be thoroughly mixed in order for the composite sample to be representative of the effluent release.

(6) Not required unless the Essential Service Water RCFC Outlet Radiation Monitors RE-PRO02 and RE-PRO03 indicates measured levels greater than lx1 06 gCi/ml above background at any time during the week.

(7) The principal gamma emitters for which the LLD specification applies include the following radionuclides:

Mn-54, Fe-59, Co-58, Co-60, Zn-65, Mo-99, Cs-1 34, Cs-1 37, and Ce-141. Ce-144 shall also be measured, but with an LLD of 5E-06. This list does not mean that only these nuclides are to be considered.

Other gamma peaks that are identifiable, together with those of the above nuclides, shall also be analyzed and reported in the Radioactive Effluent Release Report pursuant to Section 12.6.2, in the format outlined in Regulatory Guide 1.21, Appendix B, Revision 1, June 1974.

(8) A continuous release, is the discharge of dissolved and entrained gaseous waste from a nondiscrete liquid volume.

12.3.2 Dose Operability Requirements 12.3.2.A The dose or dose commitment to a MEMBER OF THE PUBLIC from radioactive materials in liquid effluents released, from each unit, to UNRESTRICTED AREAS (see Braidwood Station ODCM Annex, Appendix F, Figure F-i) shall be limited:

1. During any calendar quarter to less than or equal to 1.5 mrems to the whole body and to less than or equal to 5 mrems to any organ, and
2. During any calendar year to less than or equal to 3 mrems to the whole body and to less than or equal to 10 mrems to any organ.

91

Attachment 10 Page 11 of 14 Applicability: At all times.

Action:

1. With the calculated dose from the release of radioactive materials in liquid effluents exceeding any of the above limits, prepare and submit to the Commission within 30 days, pursuant to 10 CFR 50 Appendix I, Section IV.A, a Special Report that identifies the cause(s) for exceeding the limit(s) and defines the corrective actions that have been taken to reduce the releases and the proposed corrective actions to be taken to assure that subsequent releases will be in compliance with the above limits.

Surveillance Requirements 12.3.2.B Cumulative dose contributions from liquid effluents for the current calendar quarter and the current calendar year shall be determined in accordance with the methodology and parameters in the ODOM at least once per 31 days.

Bases 12.3.2.C This section is provided to implement the requirements of Sections II.A, Ili.A and IV.A of Appendix 1,10 CFR 50. The Operability Requirements implement the guides set forth in Section II.A of Appendix I. The ACTION statements provide the required operating flexibility and at the same time implement the guides set forth in Section IV.A of Appendix I to assure that the releases of radioactive material in liquid effluents to UNRESTRICTED AREAS will be kept "as low as is reasonably achievable." The dose calculation methodology and parameters in the ODCM implement the requirements in Section Ili.A of Appendix I that conformance with the guides of Appendix I be shown by calculational procedures based on models and data, such that the actual exposure of a MEMBER OF THE PUBLIC through appropriate pathways is unlikely to be substantially underestimated.

The equations specified in the ODCM for calculating the doses due to the actual release rates of radioactive materials in liquid effluents are consistent with the methodology provided in Regulatory Guide 1.109, "Calculation of Annual Doses to Man From Routine Releases of Reactor Effluents For the Purpose of Evaluating Compliance with 10 CFR 50, Appendix I" Revision 1, October 1977 and Regulatory Guide 1.113, "Estimating Aquatic Dispersion of Effluents from Accidental and Routine Reactor Releases for the Purpose of Implementing Appendix I," April 1977.

This section applies to the release of radioactive materials in liquid effluents from each reactor at the site. When shared Radwaste Treatment Systems are used by more than one unit on a site, the wastes from all units are mixed for shared treatment; by such mixing, the effluent releases cannot accurately be ascribed to a specific unit. An estimate should be made of the contributions from each unit based on input conditions, e.g., flow rates and radioactivity concentrations, or, if not practicable, the treated effluent releases may be allocated equally to each of the radioactive waste producing units sharing the Radwaste Treatment System. For determining conformance to Operability Requirements, these allocations from shared Radwaste Treatment Systems 92

Attachment 10 Page 12 of 14 are to be added to the releases specifically attributed to each unit to obtain the total releases per unit.

12.3.3 Liquid Radwaste Treatment System Operability Requirements 12.3.3.A The Liquid Radwaste Treatment System shall be OPERABLE and appropriate portions of the system shall be used to reduce releases of radioactivity when the projected doses due to the liquid effluent, from each unit, to UNRESTRICTED AREAS (see Braidwood Station ODCM Annex, Appendix F, Figure F-i) would exceed 0.06 mrem to the whole body or 0.2 mrem to any organ in a 31-day period.

Applicability: At all times.

Action:

1. With radioactive liquid waste being discharged without treatment and in excess of the above limits and any portion of the Liquid Radwaste Treatment System not in operation, prepare and submit to the Commission within 30 days, pursuant to 10 CFR 50 Appendix I, Section IV.A, a Special Report that includes the following information:
a. Explanation of why liquid radwaste was being discharged without treatment, identification of any inoperable equipment or subsystems, and the reason for the inoperability,
b. Action(s) taken to restore the inoperable equipment to OPERABLE status, and
c. Summary description of action(s) taken to prevent a recurrence.

Surveillance Requirements 12.3.3.B.1 Doses due to liquid releases from each unit to UNRESTRICTED AREAS shall be projected at least once per 31 days in accordance With the methodology and parameters in the ODCM when the Liquid Radwaste Treatment System is not being fully utilized.

12.3.3.B.2 The installed Liquid Radwaste Treatment System shall be considered OPERABLE by meeting Sections 12.3.1.A and 12.3.2.A.

Bases 12.3.3.C The OPERABILITY of the Liquid Radwaste Treatment System ensures that this system will be available for use whenever liquid effluents require treatment prior to release to the environment. The requirement that the appropriate portions of this system be used when specified provides assurance that the releases of radioactive materials in liquid effluents will be kept "as low as is reasonably achievable". This section implements the requirements of 10 CFR 50.36a, General Design Criterion 60 of Appendix A to 10 CFR 50 and the design objective given in Section 11.D of Appendix I-to 10 CFR 50.

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Attachment 10 Page 13 of 14 The specified limits governing the use of appropriate portions of the Liquid Radwaste Treatment System were specified as a suitable fraction of the dose design objectives set forth in Section II.A of Appendix 1, 10 CFR 50, for liquid effluents.

This section applies to the release of radioactive materials in liquid effluents from each unit at the site. When shared Radwaste Treatment Systems are used by more than one unit on a site, the wastes from all units are mixed for shared treatment; by such mixing, the effluent releases cannot accurately be ascribed to a specific unit. An estimate should be made of the contributions from each unit based on input conditions, e.g., flow rates and radioactivity concentrations, or, if not practicable, the treated effluent releases may be allocated equally to each of the radioactive waste producing units sharing the Radwaste Treatment System.

For determining conformance to Operability Requirements, these allocations from shared Radwaste Treatment Systems are to be added to the releases specifically attributed to each unit to obtain the total releases per unit.

Radiological Environmental Monitoringq Program (REMP)

Braidwood ODCM Table 12.5-1 section 3.a, Ground / well water specifies that samples from two sources are required only if they are likely to be affected. Note (6) of ODCM Table 12.5-1 clarifies that groundwater samples shall be taken when this source is tapped for drinking or irrigation purposes in areas where the hydraulic gradient or recharge properties are suitable for contamination. Per discussion with Conestoga-Rovers & Associates and the Exelon Hydrologist, onsite groundwater at Braidwood meets the above criteria. There are drinking water wells in close proximity of the site that could be affected. However, there are no specific groundwater sample locations identified in the REMP. This requirement should be reviewed to determine the groundwater monitoring required to meetthe requirements of Table 12.5-1.

Review of Braidwood ODCM Table 11-1 section 3.a, Ground / well water indicates that there are (5) drinking water wells currently being monitored.

Braidwood ODCM Table 12.5-1 Section 3.a and note (6) to the table discusses the need for groundwater monitoring when the irrigation pathway is a credible pathway. The hydraulic gradient at Braidwood indicates that shallow wells could become contaminated. ODCM Section 4.3 states that the only liquid pathways used are the potable water and fish ingestion pathways. The irrigation to food crop pathway associated with the groundwater contamination should be evaluated. (CAll)

Monitoring for other nuclides 40 CFR 141 and 35 IAC 620 specify limits on radionuclides other than tritium. As part of Braidwood's recovery plan, gamma-emitting fission and activation products as well as other beta-emitting nuclides (Strontium-89, and Strontium-90) are being analyzed. The gamma-emitting nuclide analytical results indicate normal background levels. Strontium-89 and Strontium-90 results indicate normal background levels.

94

Attachment 10 Page 14 of 14 Generic Chapters Revision 3 January, 2002 Table 2-1 Regulatory Dose Limit Matrix REGULATION DOSE TYPE DOSE LIMIT(s) 3 ODCM EQUATION Liquid Releases: (quarterly) (annual) 10 CFR 50 App. V3 Whole (Total) Body Dose 1.5 mrem 3 mrem A-17 (per reactor unit)

Organ Dose (per reactor unit) 5 mrem 10 mrem A-17 Technical Specifications The concentration of radioactivity in liquid Ten (10) times the effluents released to unrestricted areas concentration values listed A-21 in 10 CFR 20 Appendix B; Table 2, Column 2, Table C-6 of ODCM Appendix C for Noble Gases Total Doses 1:

10 CFR 20.1301 (a)(1) Total Effective Dose Equivalent 4 100 mrem/yr A-25 10 CFR 20.1301 (d) Total Body Dose 25 mrem/_yr A-25 and 40 CFR 190 Thyroid Dose 75 mrem/yr A-25 Other Organ Dose 25 mrem__/yr A-25 Other Limits 2:

40 CFR 141 Total Body Dose Due to Drinking Water From 4 mrem/yr A-17 Public Water Systems Organ Dose Due to Drinking Water From 4 mrem/yr A- 17 Public Water Systems 1 These doses are calculated considering all sources of radiation and radioactivity in effluents.

2 These limits are not directly applicable to nuclear power stations. They are applicable to the owners or operators of public water systems. However, the RETS of some of the Exelon Nuclear power stations require assessment of compliance with these limits. For additional information, see Section A.6 of Appendix A.

3 Note that 10 CFR 50 provides design objectives not limits.

4 Compliance with 10 CFR 20.1301(a)(1) is demonstrated by compliance with 40 CFR 190. Note that it may be necessary to address dose from onsite activity by members of the public as well.

95

Attachment 11 Root Cause Report Quality Checklist

.Page 1 of 2.

A. Critical Content Attributes YES NO

1. Is the condition that requires resolution adequately and accurately identified? X
2. Are inappropriate actions and equipment failures (causal factors) identified? X
3. Are the causes accurately identified, including root causes and contributing causes? X
4. Are there corrective actions to prevent recurrence identified for each root cause and do they tie DIRECTLY to the root cause?

AND, are there corrective actions for contributing cause and do X they tie DIRECTLY to the contributing cause?

5. Have the root cause analysis techniques been appropriately used and documented? X
6. Was an Event and Causal Factors Chart properly prepared? X
7. Does the report adequately and accurately address the extent of condition in accordance with the guidance provided in X Attachment 3 of LS-AA-125-1003, Reference 4.3?
8. Does the report adequately and accurately address plant specific risk consequences? X
9. Does the report adequately and accurately address programmatic and organizational issues? X
10. Have previoussimilar events been evaluated? Has an Operating Experience database search been performed to determine whether the problem was preventable if industry experience X had been adequately implemented?

96

Attachment 11 Root Cause Report Quality Checklist Page 2 of 2 B. Important Content Attributes

1. Are all of the important facts included in the report? X
2. Does the report explain the logic used to arrive at the X conclusions?
3. If appropriate, does the report explain what root causes were X considered, but eliminated from further consideration and the bases for their elimination from consideration?
4. Does the report identify contributing causes, if applicable? X
5. Is it clear what conditions the corrective actions are intended to X create?
6. Are there unnecessary corrective actions that do not address the X root causes or contributing causes?
7. Is the timing for completion of each corrective action X commensurate with the importance or risk associated with the issue?

C. Miscellaneous Items

1. Did an individual who is qualified in Root Cause X Analysis prepare the report?
2. Does the Executive Summary adequately and X accurately describe the significance of the event, the event sequence, root causes, corrective actions, reportability, and previous events?
3. Do the corrective actions include an effectiveness X review for corrective actions to prevent recurrence?
4. Were ALL corrective actions entered and verified to X be in Action Tracking? "
5. Are the format, composition, and rhetoric acceptable X (grammar, typographical errors, spelling, acronyms, etc.)?

97

Attachment 12 Vacuum Breaker #3 (VB-3) and Vacuum Breaker 2 (VB-2)

Event Timeline Page l of 13 Vacuum Breaker #3 (VB-3)

December 1997

  • VB-3 was inspected (PM 00079293) with no water leakage noted.

December, 3 to 4, 1998 VB-3 was discovered leaking, due to water hammer failure of the air vent valve line (RC 38237-02). The Problem Identification Form (PIF) for this event (A1998-04324) was closed to no concern, based on the water being contained onsite and apparently personnel not aware of a tritium concern (Root Cause 4). The PIF stated that the water was in the ditch, which Exelon owns. PIF A1998-04324 stated the repair (temporary) to stop the leak was completed within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> (12/05/1998) under WO 98127749. This section of ditch is blocked at both ends. The size/amount of leakage was not recorded due to a lack of monitoring instrumentation (Other Issue "a"), but was estimated in 2000 to be similar to the 2000 VB-2 leakage at approximately 3 million gallons over a 30-day period. No integrated spill response procedure was in place to guide adequate station response. ( Root Cause 3)

December 1998 Spill Conclusion In 1998, VB-3 failed and released approximately three million gallons producing standing surface water on Braidwood property. Problem Identification Form (PIF) A1998-04324

[equivalent to today's Issue Report (IR)] was created to document and address this spill. The response to this event was to isolate the valve and repair the valve as soon as possible. The Braidwood NPDES Coordinator was notified and determined that there were no environmental concerns because the water had not reached a waterway. The environmental procedures concentrate on NPDES compliance associated with oil or hazardous materials and by design, provide no guidance on radiological spills (Failed Barriers 1 & 2).

The Reportability Manual (LS-AA-1 020 & 1110) does not reflect ODCM REMP/RETS reporting requirements for unplanned release paths (Faile.d Barriers 7-11). Also, these procedures do not reflect 35 IAC 620 groundwater tritium requirements (Failed Barriers 7-11). At the time, Operations personnel believed (through interviews) that the water leaking from the CW B/D VB was procedurally treated and approved for radiological release to the environment (Kankakee River) and they assumed it to be radiologically acceptable if it leaked to the ground.

Engineering interviews indicated that they were aware of diluted radioactive waste effluent in the CW B/D line, but since there had been no training for the requirements or the implications of a CW B/D water spill, the creation of a work request and issue report would be an adequate response to correct the leak during the next scheduled work week.

98

Attachment 12 Vacuum Breaker,#3 (VB-3) and Vacuum Breaker 2 (VB-2)

Event Timeline Page 2 of 13 The Event Screening Committee (the equivalent of today's Braidwood Senior Management Review Committee) reviewed PIF A1998-04324 and assigned no actions to inquire into or address radiological concerns. As a consequence, no action items were created to track the characterization, remediation and documentation of this spill. Radiological concerns were not recognized. There was no documentation that any spill remediation was performed. A root cause for the ineffective response was weak management review and oversight of spill response activities (Root Cause 4). In this event , the knowledgeable personnel with the radiological expertise were not brought to bear. The root cause was determined to be a lack of integrated procedural guidance to ensure proper recognition, evaluation, and timely mitigation of the spill events (Root Cause 3) to ensure proper identification, timely mitigation and evaluation of the spill events, including knowledge of local hydrology, the impact of low-level tritium leaks, and groundwater regulations.

Documentation associated with the response does not indicate recognition that a potential radioactive spill had occurred. Had it been recognized that the 1998 release of tritium to an unplanned location (the field in the vicinity of VB-3) was a radiological release, a more rigorous characterization and remediation response may have been initiated. A lack of recognition by the Operations Department personnel (who initiate and secure the release of processed radioactive waste into the CW B/D System) and/or the Radiological Protection personnel (who sample and analyze the release tanks prior to concurring with the release), would be a missed opportunity.

Additionally, the 1998 Annual Effluent Report did not contain an evaluation of the vacuum breaker radioactivity released and did not contain the associated evaluation of the dose to the public (IR 455079) & (CA-15). No documentation was located that implied a recognition of vacuum breaker leakage impact on the requirements of the ODCM, REMP, and 10CFR50.75(g).

The root cause of the large volume leaks in 1998 and 2000 is documented in Root Cause Report (RCR) 38237, which determined that the Circulating Water (CW) Blowdown (B/D)

Vacuum Breaker (VB) Valves had inadequate preventative maintenance programs and inadequate design configuration (Root Cause 1).

November 15, 2000 Condition Report (CR) A2000-04389 was written which stated that the 1998 response to PIF Al 998-04324 was inadequate, as a result of Root Cause Report (RCR) 38237/CR A2000-04281. CR A2000-04389 resulted in an action to Radiation Protection to perform a radiological evaluation under 10 CFR 50.75(g). June 18, 2001 99

Attachment 12 Vacuum Breaker #3 (VB-3) and Vacuum Breaker 2 (VB-2)

Event Timeline Page 3 of 13 CR A2001-01806 reported VB-3 leaking. WC-AA-106 did not have tritium concerns integrated into the work prioritization. At this time, there was no guidance in the CW B/D procedures to secure radiological releases when known leaks were discovered. (Root Cause 3)

Note: Little to no information could be found in PIF's or WR/WO's for this event.

Therefore, little data could be retrieved by this Root Cause Investigation Team (IR 428868) other than from personnel interviews.

July 21, 2001

  • CR A2000-04389's 10 CFR 50.75(g) Radiological Assessment Report was completed based on samples obtained in April 2001. In retrospect, the 1998 VB-3 spill site was inadequately characterized, due to the lack of groundwater assessment for tritium concentrations. Therefore, the evaluation erroneously concluded that there was no further action required.

July 23, 2001

  • Revision 2 of WO 98127749 to repair VB-3 is authorized for work by Operations. The WO comments stated that leaking water prevented work completion. The WO did not contain precautions regarding tritium leakage, due to ATI 106767-04 (May 2002) comments not being incorporated into the WO. (OtherIssue "b")

December 2001

  • VB-3 was inspected (WO 99284438) with no water leakage noted.

May 4, 2002

  • VB-3 pilot (air release) valve seat was discovered leaking water. WO 004402131 and IR 106767 were written.

100

Attachment 12 Vacuum Breaker #3 (VB-3) and Vacuum Breaker 2 (VB-2)

Event Timeline Page 4 of 13 May 20, 2002

  • Revision 2 of WO 98127749 to repair the isolation valve for VB-3 was completed, with no mention of radiological controls for the water discovered in the vacuum breaker pit. (Root Cause 3)

August 29, 2003 Water was found in the VB-3 valve pit during walkdown surveillance. WR 00110407 and IR 173688 were written. The IR indicates water is most likely groundwater intrusion into the pit. There was no observed leakage from VB-3.

March 17, 2005 The Illinois Environmental Protection Agency (IEPA) contacted Exelon concerning an investigation of tritium concentrations in wells near Braidwood Station in preparation for the Godley public hearing. Sampling to investigate this report was commenced. (IR 328451)

November 30, 2005

  • Issue Report (IR) 428868 reports tritium concentrations from what appears to be the area of the 1998 spill, have migrated offsite with a potential to affect the public via tritiated groundwater. (EVENT)

Vacuum Breaker 2 (VB-2)

December 1996

  • VB-2 was inspected (PM 00079293) with no water leakage noted.

January 5, 1998

  • Water leak discovered on the VB-2 pilot (air release) valve seat. WR 9800691 was written.

101

Attachment 12 Vacuum Breaker #3 (VB-3) and Vacuum Breaker 2 (VB-2)

Event Timeline Page 5 of 13 May 24, 2000

November 6, 2000 14:30 The Braidwood National Pollutant Discharge Elimination System (NPDES) Coordinator received a call from the Illinois Environmental Protection Agency (IEPA) regarding standing water in a ditch immediately adjacent to private property along the south side of Smiley Road. An area resident had reported the water and noted that the water had been present in the ditch for approximately 7-10 days prior to IEPA notification.

Suspecting a faulty vacuum breaker, the NPDES Coordinator notified the Shift Manager and Outage Control Center (OCC) Director of the IEPA notification.

November 6, 2000 15:00

  • The Braidwood NPDES Coordinator walked down the Circulating Water Blowdown system and identified that the water was coming from a valve vault that houses VB-2.

The NPDES Coordinator assessed the site and concluded that the water was confined to site property which included the ditch along the south side of Smiley Road.

  • The Braidwood NPDES Coordinator notified the IEPA of his findings regarding the water source and the boundaries of the discharge. Station NPDES monitoring requirements were discussed and the IEPA requested no additional sampling. The Braidwood NPDES Coordinator determined that there were no NPDES concerns since the water was contained and not discharging to "Waters of the State".
  • The VB-2 leakage was estimated to be a maximum of 3 million gallons. This leakage was the result of corrosion of the vacuum breaker assembly and water hammer, which broke the float in VB-2, exposing an 8" opening.

102

Attachment 12 Vacuum Breaker #3 (VB-3) and Vacuum Breaker 2 (VB-2)

Event Timeline Page 6 of 13 November 6, 2000 16:00 -17:00 A meeting was held with Braidwood Senior Management, the Shift Manager and the Outage Control Center (OCC) staff. The Braidwood NPDES Coordinator briefed the attendees on the results of his field observations of the area surrounding the vacuum breaker valve. Braidwood Senior Management was also briefed on the discussions between the Braidwood NPDES Coordinator and the IEPA. Braidwood Senior Management directed the following actions be taken:

1. Operating personnel were to evaluate water inventories and to explore potential alternate release options.
2. Isolate the CW B/D system
3. Make preparations to take the CW B/D system out of service, drain the piping section and replace the failed vacuum breaker valve.

The CW B/D system was then isolated in preparation for draining and repairs. There was no discussion at this time of any need to sample for radioactivity in the water that had been discharged. The thought process was that any radioactivity in the water had been diluted per procedure and was acceptable for discharge to the environment (i.e., the Kankakee River). [This is based on Operations Department personnel interviews.]

November 7, 2000 06:15

, The Braidwood Operations Manager notified the Braidwood Radiation Protection (RP)

Manager that there was a blowdown line leak and that RP was to meet with the Braidwood Chemistry Manager to look at potential alternate radioactive release paths.

The reason for this request was that radioactive releases would not be possible via the blowdown system while blowdown was isolated for repairs to VB-2.

  • Following this phone conversation, the Braidwood RP Manager notified the Braidwood RP Technical Superintendent regarding the need to collect samples of available water.

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Attachment 12 Vacuum Breaker #3 (VB-3) and Vacuum Breaker 2 (VB-2)

Event Timeline Page T7of 13 November 7, 2000 08:00 A decision to conduct confirmatory sampling of the water leaking from the manway cover of the vacuum breaker structure was made. The sample was taken at approximately 0845 and the results of the gamma isotopic analysis indicated no detectable radioactivity. Isotopic analysis indicated no detectable tritium.

  • Braidwood chemistry manager contacts corporate environmental and asks them to report to the site to help assess the event.

Decision is made by Braidwood Senior Management to sample both soil and water at the vacuum breaker.

November 7, 2000 08:30 Mechanical Maintenance Department (MMD) personnel with assistance from System Engineering pumped out the VB-2 vault back into the B/D line and began draining the blowdown piping to facilitate work on VB-2.

November 7, 2000 11:30 Braidwood RP received information that the leak may have occurred for a period of 7-10 days and that the water that leaked was from the circulating water blowdown line, which carries the liquid radiological discharges from the station to the river.

November 7, 2000 12:00

  • After the CW B/D line had drained sufficiently, the entire VB-2 isolation valve and vacuum breaker assembly was replaced.

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Attachment 12 Vacuum Breaker #3 (VB-3) and Vacuum Breaker 2 (VB-2)

Event Timeline Page8of 13a November 7, 2000 12:30

  • A decision was made to initiate soil sampling in the vicinity of the vacuum breaker structure, and to obtain a water sample from the standing water that was onsite, but near the Smiley Road ditch.

November 7, 2000 13:00

  • Braidwood RP Manager and Station Manager discuss and agree to additional sampling.

Plan was approved.

November 7, 2000 18:00

  • Braidwood management talked with local residents to explain the issue.

November 7, 2000 19:00

  • The results of the samples from November 7, 2000, were discussed with corporate Generation Support Department (GSD) RP Manager. Corporate GSD agreed to discuss the issue with the corporate GSD General Manager.

November 7, 2000 19:45

  • The Station Manager and Site Vice-President (VP) were notified of the sample results. A total of 5 soil samples were obtained within approximately 30 feet of the vacuum breaker VB-2 structure, and 2 of the 5 soil samples had detectable levels of radioactivity. The onsite soil sample obtained near the Smiley Road ditch was analyzed indicated no gamma radioactivity, and water analysis from the location indicated tritium at 35,000 pCi/L.

November 7, 2000 21:15

  • Circ water blowdown is restored.

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Attachment 12 Vacuum Breaker #3 (VB-3) and Vacuum Breaker 2 (VB-2)

Event Timeline Page9of 13 November 8, 2000 08:30

  • The Braidwood RP Manager discussed the sample results on the morning call.

November 8, 2000 14:00

  • The Braidwood RP Manager, Chemistry Manager, Regulatory Assurance Manager, Station Manager, and Site VP met to discuss the current status, next steps, and sampling for the event.

November 8, 2000 16:00 Additional onsite sampling of the standing water in the area leading to the Smiley Road ditch was performed. Four water samples were taken and results indicated tritium levels ranging from 35,000 to 53,000 pCi/L. No gamma isotopic activity was detected in the water.

November 8, 2000 18:00

  • Conference call between site and corporate regarding test results and proposed actions.

November 9, 2000 10:00 A conference call was held with the Site Management and Corporate Personnel to finalize and approve an Offsite Sampling Plan, a Remediation Plan, and a Communications Plan. At 12:00, discussions were held with site and regional NRC personnel. At 1210, notification of the offsite release was made to Will County authorities and to the Reed Township Highway Commissioner. At 12:45, RP was dispatched to obtain water samples from the Smiley Road ditch.

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Attachment 12 Vacuum Breaker #3 (VB-3) and Vacuum Breaker 2 (VB-2)

Event Timeline Page 10 of 13 November 9, 2000 14:00 Four water samples were obtained from the Smiley Road ditch. Gamma isotopic analysis indicated and the tritium analyses ranged from 19,000 pCi/L to 25,000 pCi/L NQPF.

Teledyne Isotopes Midwest Laboratory also analyzed these samples with similar results.

November 9, 2000 17:30

November 10, 2000 01:00

  • IDNS came to the site to take (4) samples from the Smiley Road ditch.

November 10, 2000 11:00

  • Pumping of the water back to the blowdown line commenced. Pumping continued using a 600 gpm pump, approximately 18 hours2.083333e-4 days <br />0.005 hours <br />2.97619e-5 weeks <br />6.849e-6 months <br /> per day.
  • Corporate led remediation team formed and OP-AA-101-503 "NGG Issue Management Worksheet" was entered. Attachment 2 (action plan) of this procedure was created and approved.

November 2000 Spill Conclusions In 2000, VB-2 failed and released approximately three million gallons to the Braidwood Station grounds. A local resident observed and reported the spill to the Illinois Environmental Protection Agency (IEPA), who in turn notified the Braidwood Station National Pollutant Discharge Elimination System (NPDES) Coordinator. The NPDES Coordinator wrote PIF A2000-04281 and notified the Illinois Department of Nuclear Safety (IDNS), the Illinois Emergency Management Agency (IEMA) and Braidwood Senior Management. The Braidwood Radiation Protection (RP) Manager and the RP Technical Superintendent discussed the need to collect samples of available water at VB-2. The sample results indicated >20,000 pCi/L tritium was present in the spilled water. The immediate response to this event was to shutdown the blowdown system, repair the valve as soon as possible, and engage Senior Corporate Management to create a spill response plan.

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Attachment 12 Vacuum Breaker #3 (VB-3) and Vacuum Breaker 2 (VB-2)

Event Timeline Page 11 of 13 A Senior Corporate Manager was chosen to assemble and direct an Issues Management Team (IMT). Although knowledgeable personnel supported the IMT, there was no integrated procedure in place to ensure that all necessary actions were completed (Root Cause 3). As a result, the groundwater tritium was not properly characterized and remediated.

The IMT entered four (4) Corporate procedures, which provide guidance to identify, evaluate, remediate and communicate the radiological concerns. The four (4) procedures were:

  • NSP-RP-61 01, "10 CFR 50. 75(g)(1) Documentation Requirements" 0 CWPI-NSP-1 -1, "CAP Process Manual of Common Work Practice Instructions -

Instruction on Event Response Guidelines'

  • OP-AA-1 01-501, "NGG Significant Event Reporting' 0 OP-AA-1 01-503, "NGG Issues Managemenf'.

However, no historical documentation could be located to demonstrate that the procedures (other than NSP-RP-61 01) were fully executed. There is no evidence of the use of Passport for the documentation of the IMT plans and activities as required by OP-AA-101-503, "NGG Issues Management". This root cause team interviewed (by telephone) the Corporate Senior Manager who was assigned to manage the Issues Management Team. He was questioned concerning the execution of the IMT's responsibilities. The Corporate Senior Manager had little recollection of the details of the team's response. Although that Corporate Senior Manager had the responsibility to manage the IMT's completion of characterization and remediation plans and would normally be held accountable, he is no longer employed by Exelon. This indicates weak management review and oversight of spill response activities. (Root Cause 4)

The IMT developed separate soil sampling plans and water sampling plans flowcharts (decision trees). For soil, all documentation was done within the station 10 CFR 50.75(g) procedure, NSP-RP-6101. For water, the sampling plan included a review of the tritium in the water and implementation of a Remediation/Control Plan. Notes on the water sampling plan indicate that the team considered: 1) pumping the water back into the blowdown line and 2) well monitoring.

The IMT had also recognized the need to evaluate local hydrology for potential impact of the tritiated spill in groundwater as referenced in a contractor's proposal for the implementation of a Stage 1 and Stage 2 plan. Stage 1 included the installation of wells to assess the local hydrology to determine groundwater gradients and movement . This stage of the plan was executed by the IMT. Stage 2 of the plan included sampling of the groundwater to determine mixing model and surface infiltration into an aquifer. Stage 2 of the plan was not executed.

The water was pumped back into the B/D line on 11/10/00 and hydrology wells were installed in the area of the 2000 leak to characterize the local hydrology. The contractor report specified that the groundwater in the area of VB-2 would take 15 years to travel the 800 feet to reach the property line.

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Attachment 12 Vacuum Breaker #3 (VB-3) and Vacuum Breaker 2 (VB-2)

Event Timeline Page 12 of 13 The report then clarifies that the flow velocity would not apply to the surface water that apparently flowed from the valve box, over the land surface, and to the ditch along the road.

The remediation efforts were halted after the surface water was pumped back into the B/D line Although no documentation exists for the basis behind the decision to not perform groundwater sampling, a review of IMT data and, notes has lead the Root Cause Investigation Team to Conclude that the following information was considered in the decision making process:

  • The spilled water had already been approved for release. Therefore, it was already determined to meet concentration limits for release to the public. The team assessed the impact of the radiological spill against known reporting requirements. The Illinois Groundwater statute was absent from the list in the IMT notes (Causal Factor 4).
  • The hydrology study indicated that it would be. 15 years before groundwater in the area of VB-2 would migrate offsite to potentially impact offsite drinking water wells. At that rate, the tritium concentration would be below drinking water standards, potentially even below detectable levels, by the time it reached the site boundary due to radiological decay and, potentially, dilution. [Today, hydrology experts state that once the tritium enters the groundwater, dilution does not significantly occur.]

Further efforts included a 10 CFR 50.75(g) characterization study. The 2000 10 CFR 50.75(g) focused primarily on soil sampling. The 10 CFR 50.75(g) study does reference the tritium concentrations that were found in the standing water. The 10 CFR 50.75(g) study did not direct groundwater sampling for tritium nor assess the environmental impact of the spilled tritium (Failed Barrier 3). The 2000 RCR Team required an analysis of the 2000 leak 10 CFR 50.75(g) by an independent Certified Health Physicist and approval by Braidwood Senior Management, however, this analysis did not include tritium. As a result, the groundwater tritium went undetected until the 2005 tritium sampling discovered it. This indicates weak management review and oversight of spill response activities. (Root Cause 4)

The year 2000 leak from Vacuum Breaker (VB) 2, RCR # 38237 documented 5 CW B/D vacuum breaker spills. Two of these released a large volume of water. The root-cause of these leaks was inadequate preventative maintenance programs and inadequate design configuration (Root Cause 1). Effectiveness Review (EFR) of the Corrective Actions to Prevent Recurrence (CAPRs) of large volume leaks determined that the CAPRs were effective at resolving the Root Cause. However, the Root Cause was narrowly defined, only evaluating the large volume valve leaks and not considering radiological impacts from the spills due to a lack of technical rigor (CAPR 3 and CAPR 5 address this issue).

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Attachment 12 Vacuum Breaker #3 (VB-3) and Vacuum Breaker 2 (VB-2)

Event Timeline Page 13 of 13 The 2000 Root Cause Report (RCR) Team discovered the large volume 1998 VB-3 leak and wrote PIF A2000-04281 to have the 1998 spill reviewed per procedure # NSP-RP-6101 for residual radioactivity under 10 CFR 50.75(g). The soil sampling conducted as part of the 10 CFR 50.75(g) process indicated similar deposited radionuclides in the soil as that found during the 2000 leak. However, tritium was not addressed (Failed Barrier 3).

Braidwood Senior Management and Exelon Corporate Senior Management did not track characterization and mitigation plans to completion during and following the year 2000 spill.

Although the 2000 Annual Effluent Report did report the 2000 vacuum breaker leakage as an unplanned release, it did not contain a proper assessment of the dose to the public. The 1998 Annual Effluent Report was not amended to report the 1998 vacuum breaker leakage (discovered in 2000) and associated dose to the public (IR 455079) & (CA-15).

HU-AA-102 and -1212, Technical Human Performance Practices and Technical Task Risk/Rigor Assessment, Pre-Job Brief, Independent Third Party Review, and Post-Job Brief procedures have been instituted to improve technical rigor, questioning attitude, and attention to detail (CAPR 3). OP-AA-106-101-1002, Exelon Nuclear Issues Management, will be revised to: 1) improve Corrective Action Program (CAP) controls of Issue Management Teams, 2) utilize the tools and techniques of the Exelon HU-AA-102 and -1212, Technical Human Performance Practices and Technical Task Risk/Rigor Assessment, Pre-Job Brief, Independent Third Party Review, and Post-Job Brief procedures, 3) strengthen reporting requirements to station Senior Management, and 4) define station Senior Management responsibilities oversight and challenge of events and issues from initiation to final disposition (CAPR 5).

An email from an RP supervisor who attended an exit meeting for an NRC REMP (radiological effluent monitoring program) inspection (NRC Inspection Report Braidwood 2001-0005) provided the following information. The Nuclear Regulatory Commission (NRC) reviewed the 2000 Root Cause (RC 38237) (documented in NRC Inspection Report Braidwood 2001-0005) and had a recommendation to sample residential wells in the area of concern "just to see negative results from these locations to support future cleanup activities" (documented only in the email). A second comment from the NRC review was that the root cause only focused on the equipment issues and not on spill recovery aspects. No documentation could be found to show that the Issues Management Team or Braidwood Senior Management reacted to these NRC's observations. This response reflects a weak management review and oversight of spill response activities (Root Cause 4). A contributing cause to this overall event was a weak questioning attitude and an inadequate challenge culture by Braidwood Senior Management regarding the 17 CW B/D leaks over the 10 year period bridging 1996 to the present.

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