Information Notice 2006-13, Ground-Water Contamination Due to Undetected Leakage of Radioactive Water: Difference between revisions

From kanterella
Jump to navigation Jump to search
← Older edit
VisualWikitext
Created page by program invented by StriderTol
Created page by program invented by StriderTol
 
Line 1: Line 1:
{{Adams
#REDIRECT [[Information Notice 2006-13, E-mail from M. Mclaughlin on NRC, Regarding NRC Information Notice 2006-13: Groundwater Contamination]]
| number = ML060540038
| issue date = 07/10/2006
| title = Ground-Water Contamination Due to Undetected Leakage of Radioactive Water
| author name = Miller C L, Nieh H K
| author affiliation = NRC/NMSS/IMNS, NRC/NRR/ADRA/DPR
| addressee name =
| addressee affiliation =
| docket = 05000213, 05000237, 05000247, 05000249, 05000286, 05000454, 05000455, 05000456, 05000457
| license number = DPR-019, DPR-025, DPR-026, DPR-061, NPF-037, NPF-072, NPF-077
| contact person = Markley A W, NRR/DPR/PGCB, 415-3165
| case reference number = FOIA/PA-2006-0314, FOIA/PA-2010-0209
| document report number = IN-06-013
| document type = NRC Information Notice
| page count = 10
}}
{{#Wiki_filter:UNITED STATES
 
===NUCLEAR REGULATORY COMMISSION===
OFFICE OF NUCLEAR REACTOR REGULATION
 
WASHINGTON, D.C.  20555-0001 July 10, 2006NRC INFORMATION NOTICE 2006-13:GROUND-WATER CONTAMINATION DUE TO
 
===UNDETECTED LEAKAGE OF RADIOACTIVE===
 
WATER
 
==ADDRESSEES==
All holders of operating licenses for nuclear power and research and test reactors including
 
those who have permanently ceased operations
 
and have certified that fuel has been
 
permanently removed from the reactor and those authorized by Title 10 of the
 
Code of Federal
 
Regulations
 
(10 CFR) Part 72 licenses to store spent fuel in water-filled structures.
 
==PURPOSE==
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice (IN) to inform
 
addressees of the occurrence of radioactive contamination of ground water at multiple facilities
 
due to undetected leakage from facility structures, systems, or components that contain or
 
transport radioactive fluids.  It is expected that recipients will review the information for
 
applicability to their facilities and consider actions, as appropriate, to avoid similar problems.
 
However, suggestions contained in this IN are not NRC requirements; therefore, no specific
 
action or written response is required.
 
==DESCRIPTION OF CIRCUMSTANCES==
Radioactive contamination of ground water has occurred at multiple facilities due to undetected
 
leakage from facility structures, systems, or components that contain or transport radioactive
 
fluids.  Specific instances that have occurred recently include the following:
 
===Braidwood Nuclear Power Plant===
In March 2005, the licensee was notified by the Illinois Environmental Protection Agency (EPA)
of tritium detected in a nearby residential well.  Following that notification, the licensee began
 
monitoring ground water between the community and the Braidwood plant.  The licensee found
 
detectable levels of tritium in a drainage ditch near the Braidwood access road, but at that time, no other offsite contaminated ground water was found.  Based on the tritium identified in the
 
drainage ditch, the licensee installed additional onsite monitoring wells to identify the source of
 
the tritium contamination.
 
In November 2005, the licensee identified peak contaminated ground water levels of
 
58,000 picocuries per liter (pCi/L) in shallow, ground-water monitoring wells located at the edge
 
of the owner controlled area.  The licensee notified the NRC and immediately suspended all
 
further liquid radioactive releases.  The tritium was attributed to historical leakage from vacuum
 
breakers along the circulating water system blowdown line that is routinely used for radioactive
 
liquid releases.
 
ML060540038 Although the Braidwood piping was below ground, the vacuum breaker valve vaults
 
communicate with the surface.  Consequently, the leaks were both above and below ground. The licensee subsequently determined that onsite radioactive leakage from the blowdown
 
system had occurred in 1996 (250,000 gallons), in 1998 (3,000,000 gallons), and in 2000
 
(3,000,000 gallons).  Onsite tritium levels measured in a deep onsite ground-water monitoring
 
well measured as high as 282,000 pCi/L.  Offsite tritium levels measured up to 1,600 pCi/L in a
 
residential well, below the Federal EPA drinking water standard of 20,000 pCi/L.  The licensee
 
characterized the extent and magnitude of the tritium ground-water contamination as an area
 
that extended about 2,000 feet by 2,500 feet outside the site boundary.  The licensee's
 
radiological assessment for the hypothetical, maximally exposed individual indicates that the
 
dose consequence would be about 0.16 millirem per year (i.e., about 5 percent of the "as low as
 
reasonably achievable" (ALARA) criteria for nuclear plant design objectives and limiting
 
conditions for operation).
 
The NRC inspection found that the licensee did not (1) adequately evaluate the radiological
 
hazards associated with the leakage; (2) calculate dose to member(s) of the public; (3) revise its
 
environmental monitoring program to adequatel
 
y measure the impact to the environment;
(4) report aspects of the leakage in its annual effluent report; and (5) record the residual
 
contamination in files for decommissioning purposes (NRC Inspection Reports Nos. 50-456;
 
457/2006-02, Agency Wide Documents Access
 
and Management System (ADAMS) Accession
 
No. ML061360416, and 50-456; 457/2006-008, ADAMS Accession No. ML 061450522).
 
===Byron Nuclear Power Plant===
Following the identification of tritium leakage at Braidwood, the licensee initiated a sampling and
 
analysis program along the Byron circulating wa
 
ter system blowdown line.  Similar to the
 
Braidwood facility, the Byron blowdown line has
 
six vacuum breakers located in valve vaults
 
located on plant property.  Standing water in the vaults was sampled and analyzed, with five of
 
the six vaults having detectable levels of tritium up to 80,000 pCi/L.  The licensee suspended all
 
radioactive liquid effluent releases through the blowdown line.
 
Residential wells were sampled and found not to have any detectable contamination.  Additional
 
monitoring wells were installed near the valve vaults and detectable levels of tritium have been
 
found near two of the valve vaults.  By April 2006, the licensee had completed repairs to the
 
vacuum breakers and vaults, including sealing the vault floors.  After repairs were completed, the licensee recommenced liquid effluent discharges through the circulating water system
 
blowdown line (NRC Preliminary Notifications Nos. PNO-III-06-004 and PNO-III-06-004B).
 
===Dresden Nuclear Power Station===
In August 2004, the licensee identified contaminated ground water in onsite monitoring wells
 
resulting from a leaking underground pipe connected to the condensate storage tanks.
 
Subsequent, onsite sampling identified tritium levels consistent with those present in the
 
condensate storage tank of about 8,000,000 pCi/L.  The licensee isolated the leaking pipe and
 
replaced the faulty section of piping.
 
Following the 2004 leak, the licensee sampled the private wells of nearby residents.  One of the
 
residents' wells that had shown detectable tritium for a number of years had tritium levels of
 
approximately 1,000 pCi/L.
 
Additionally, three other residential wells were found to have measurable but lower levels of
 
tritium.  The  licensee continues to evaluate the tritium in those wells, one of which is the normal
 
sample point for its radiological environmental monitoring program. In February 2006, tritium levels of 600,000 pCi/L were detected in an onsite monitoring well near
 
a section of underground piping that had not been replaced in 2004.  The leaking pipe was
 
isolated and onsite tritium levels in the two closest onsite wells subsequently stabilized at
 
20,000 - 50,000 pCi/L (NRC Inspection Report Nos. 50-237; 239/2006-03, ADAMS Accession
 
No. ML061290091).
 
Haddam Neck Station (Connecticut Yankee Atomic Power Plant)
The Haddam Neck Station ceased operations about 10 years ago and is being decommissioned
 
under an approved NRC license termination plan (LTP).  The licensee's monitoring programs
 
have not identified any offsite ground-water contamination associated with plant operations.
 
An onsite ground-water monitoring program has been established and is being implemented in
 
support of the decommissioning.  The licensee initially identified tritium, cobalt-60, cesium-137
 
and strontium-90 in the onsite ground water and/or soil samples.  The licensee has removed a
 
large amount of soil and some bedrock, and backfilled the excavated areas with clean soil.
 
While the licensee has substantially reduced residual contamination levels, recent ground-water
 
sampling results have identified residual tritium up to 19,500 pCi/L, cesium-137 up to 12 pCi/L
 
and strontium-90 up to 4.5 pCi/L.  The licensee has completed dose assessments for the
 
existing onsite ground-water contamination in accordance with the LTP.  The dose assessments
 
indicate a dose contribution of less than 1 millirem per year due to the ground-water
 
contamination.
 
The NRC license termination requirement is that the all-pathways, total effective dose
 
equivalent to the average member of the critical group does not exceed the 10 CFR 20.1402
 
unrestricted release requirement of 25 millirem
 
per year and the residual radioactivity has been
 
reduced to ALARA.  This includes the soil
 
exposure pathway, existing groundwater dose
 
contributions and future groundwater dose contributions.  Additionally, the licensee must comply
 
with requirements by the State of Connecticut's Department of Environmental Protection to
 
meet the Federal EPA Maximum Contaminant Levels.  The most recent NRC onsite inspection
 
is documented in NRC Inspection Report No. 50-213/2005-03, ADAMS Accession No.
 
ML060390475.
 
Indian Point Nuclear Generating Station Units 1, 2, and 3 In September 2005, the licensee identified leakage of contaminated water from cracks in the
 
Unit 2 spent fuel pool (SFP), and subsequently discovered tritium contaminated ground water, about 200,000 pCi/L, in a monitoring well located in the Unit 2 transformer yard.  Upon
 
discovery of this condition, the licensee initiated extensive efforts to characterize the nature and
 
source of the ground-water contamination.  Efforts included the installation of a series of
 
instrumented monitoring wells, comprehensive
 
hydrological and geophysical assessment of the
 
site, engineering efforts to determine the source of contamination, and enhancements to onsite
 
and offsite radiological environmental monitoring.
 
Extensive efforts were also made by the
 
licensee and NRC to keep members of the public and interested local, state, and federal
 
stakeholders informed of progress and developments in the site characterization, and plans to
 
effect resolution of the ground-water contamination.
 
Onsite ground-water tritium concentrations have been measured as high as about
 
600,000 pCi/L in the immediate vicinity of the Unit 2 SFP.  Strontium-90 contamination has also
 
been identified in ground water in the vicinity of the Unit 1 decommissioned facility which has
 
been in SAFSTOR since 1974.  The current hydrological assessment indicates that ground water is likely migrating into the Hudson River.  A conservative radiological assessment for the
 
maximally exposed individual indicates that the dose consequence would be about 0.01 millirem
 
per year (i.e., about 0.1 percent of ALARA criteria for nuclear plant design objectives and
 
limiting conditions for operation).
 
NRC Inspection Report 50-247/2005-11, dated March 16, 2006 (ADAMS Accession No.
 
ML060750842), documented the results of an NRC special inspection that was conducted to
 
review and assess the events and circumstances in this case.  While the inspection reached
 
important safety conclusions, significant licensee performance deficiencies were not identified.
 
However, NRC inspection activities are continuing to review the licensee efforts and progress to
 
support a final regulatory conclusion.
 
==BACKGROUND==
NRC requirements related to the radioactive liquid effluents include: 
10 CFR 20.1301(a)(1) - requires that each licensee conduct operations so that the total effective
 
dose equivalent to individual members of the public from the licensed operation does not
 
exceed 100 millirem (1 mSv) in a year.
 
10 CFR 20.1302 - requires licensees to perform appropriate surveys in unrestricted areas and
 
controlled areas to demonstrate compliance with dose limits for individual members of the
 
public.10 CFR 20.1501 - requires, in part, that licensees conduct surveys that are reasonable under
 
the circumstances to evaluate the concentrations or quantities of radioactive material and the
 
potential radiological hazards.
 
10 CFR Part 50, Appendix I, Section II.A - establishes the design objectives and limiting
 
conditions for operation to meet ALARA criteria such that the calculated annual total quantity of
 
all radioactive material above background released to unrestricted areas will not result in an
 
estimated annual dose or dose commitment from li
 
quid effluents in excess of 3 millirems to the
 
total body or 10 millirems to any organ.
 
10 CFR Part 50, Appendix A, Criterion 64 - requires, in part, that a means be provided for
 
monitoring effluent discharge paths, and the plant environs for radioactivity that may be
 
released from normal operations.  To meet this
 
regulation, licensees implement a Radiological
 
Environmental Monitoring Program (REMP) wh
 
ich provides for ground-water monitoring.
 
However, the REMP program is designed to validate the results of the licensee's normal
 
radioactive gaseous and liquid effluent release programs for dose assessment in the
 
Unrestricted Area.  Consequently, the data from the REMP program may not provide a full
 
understanding of the extent, types, and movement of potentially undetected radioactive
 
contamination in onsite ground water within the Restricted Area.  NRC Regulatory Issue
 
Summary 2002-02, "Lessons Learned Related to Recently Submitted Decommissioning Plans
 
and License Termination Plans," dated January 16, 2002, provides additional information in this
 
regard (ADAMS Accession No. ML013510432).
 
10 CFR 50.75(g)(1) - requires, in part, that each licensee keep a record of spills or other
 
unusual occurrences involving the spread of contamination in and around the facility or site.
 
These records must include any known information on identification of involved nuclides, quantities, forms, and concentrations.  Such documentation in a decommissioning record file is important to provide a database for site characterization during decommissioning, as well as, providing support for public and worker dose assessments.  NUREG-1757, "Consolidated
 
[Office of Nuclear Material Safety and Safeguards] NMSS Decommissioning Guidance,"
 
provides guidance on decommissioning record keeping (ADAMS Accession No. ML032530410).
 
10 CFR 50.72 - requires a four-hour report to NRC Operations Center when any event or
 
situation occurs, related to protection of the environment, for which a news release or
 
notification to other government agencies has been or will be made.
 
===Related Generic Communications===
NRC Information Notice 2004-05, "Spent Fuel Pool Leakage to Onsite Ground Water," dated
 
March 3, 2004, (ADAMS Accession No. ML040580454) discussed SFP leakage at Salem
 
Station Unit 1 to the onsite ground water, including potential impact to the public and workers, and the structural integrity of the SFP.  The NRC noted that leaks can develop in SFPs and go
 
undetected for long periods of time absent appropriate monitoring, resulting in the
 
contamination of onsite ground water and the potential for undetected, unevaluated releases of
 
radioactivity to an unrestricted area.
 
==DISCUSSION==
NRC reviews to-date have identified the following important points associated with ground-water
 
contamination events: 1. Leakage from structures, systems, or co
 
mponents that contain and transport radioactive
 
fluids can contribute, over long periods of time, to extensive ground-water contamination.
 
This leakage may not be easily detectable due to small leakage rates or because the
 
area near the point of leakage is not subject to routine radiological monitoring.  Leakage
 
from underground piping at Braidwood released substantial quantities of contaminated
 
water to onsite ground water.  Representative sampling and analysis of onsite ground
 
water may be the only viable method to detect this leakage and the subsequent
 
migration of the contamination, particularly for subsurface leakage (e.g., buried pipe
 
leakage).2.Existing NRC regulations do not explicitly mandate routine onsite ground-water
 
monitoring in the Restricted Area during facility operations.  If the contamination is
 
detected by environmental monitoring at or beyond the site boundary under the REMP,
extensive contamination may have already
 
occurred that could have been contained if
 
detected sooner.  Further, although licensees may be sampling onsite drinking water as
 
part of its REMP, this water may originate from deeper hydro-geologic units not affected
 
by contamination of the shallow water table hydro-geologic unit.3.The identification of onsite contamination may serve as an early indicator of degradation
 
of onsite structures, systems, or components or the need for maintenance, particularly
 
degradation caused by boric acid.  4.The principal screening method of detecting leakage at reactor sites is sampling and
 
analyses for tritium contamination.  Ho
 
wever, other analysis methods can detect radioactive gamma emitters, and consideration should be given to performing analyses
 
for typical hard-to-detect radionuclides.  These nuclides can consist of both fission or
 
activation products that may include Nickel-63, Iron-55, Strontium-90, transuranics, and
 
others.  While initial analyses may conclude the absence of gamma emitters and hard-
 
to-detect radionuclides, long-term migration may subsequently result in the transport of
 
contamination to downstream locations.  Further, a working knowledge and
 
understanding of onsite hydrology would aid
 
development of monitoring strategies, sampling plans, and selection of individual sampling locations.
 
5.Licensees typically establish onsite ground-water monitoring and sampling programs in
 
response to known, identified structure, system, or component leakage.  Once the
 
source of the leakage is repaired, it is important to objectively evaluate whether it is
 
appropriate to terminate these supplemental onsite monitoring and sampling programs, as the onsite monitoring and sampling programs may be the only reliable method for
 
detecting repeat occurrences in a timely manner, particularly for subsurface leakage.  In
 
the case of the Dresden facility, the onsite ground-water monitoring wells that had been
 
installed for previous leakage incidents were instrumental in identifying the 2006
 
leakage, which enabled a more timely identification and limited the extent of the
 
contamination.
 
6.SFP leak detection may require special te
 
chniques since SFPs have an evaporation rate
 
up to several hundred gallons per day.  This evaporation rate may mask small leaks in
 
the SFP liner and make small leakage rates difficult to detect by evaluation of make-up
 
rates within a water balance calculation.  Consequently, licensees who are not closely
 
evaluating the potential for leakage, including through-wall and/or floor leakage, may not
 
detect such leakage.  Further, the leakage may be from SFP fuel transfer tubes and may
 
only occur during refueling outages.  Because there is considerable water transfer
 
activity during refueling outages, small leakage rates may not be readily apparent during
 
make-up or transfer operations.  Other considerations include:*Licensee experience with onsite and offsite ground-water contamination as a
 
result of SFP leakage varies significantly.  Some licensees have identified large
 
areas of onsite ground-water contamination due to SFP leakage.  It is important
 
to be aware that small, long-term, undetected leaks from SFPs can result in
 
extensive areas of contamination. *Due to the difficulty in detecting single small leaks or small leaks from different
 
locations, particularly those that occur over long time periods, corrective actions
 
may involve management of leakage (e.g., collection and treatment) rather than
 
leak repair.*Some licensees have not evaluated the capability of their SFP leak detection
 
systems to detect small leaks.  Leakage trending and tracking programs can
 
supplement leakage detection systems and provide an indication of changes in
 
apparent leakage rates.  Any unexplained change in leakage rates, including a
 
reduction in leakage rates, should prompt further evaluation.*Clogging of SFP telltale drain systems could result in undetected SFP leakage.
 
Maintenance and cleaning programs for SFP telltale drain systems ensure viable
 
drain paths remain open.  Alternate methods to look for leakage are available for
 
facilities without SFP telltale drain systems. .Leakage from facility structures to the environment can itself become a source of
 
contaminated in-leakage (back into the facility) at another location.  Because stations
 
have facilities and rooms below grade level, it is not uncommon for ground water to leak
 
into the facilities.  It is important to evaluate unexpected in-leakage to determine if it is
 
contaminated ground water using radio-analytical and chemical analysis (e.g., boron).8.Radioactive contamination of subsurface rock, soil, or ground-water contamination can
 
impact decommissioning decisions.  Remediation at the time of discovery in some
 
instances could prevent significant migration to large subsurface areas that could
 
complicate and increase the cost of decommissioning.  Hydrogeology studies and the
 
addition of onsite monitoring wells should be considered to identify ground-water flow
 
patterns, support knowledge of the location and extent of contamination, to quantify
 
contaminant migration, and to support decision-making for potential remediation
 
measures.  These studies can also support an estimation of future decommissioning
 
costs. 9.  NRC's inspection program identified that there is an apparent wide variation in licensee
 
knowledge in the requirement to document the ground-water contamination issues
 
consistent with all parts of 10 CFR 50.75(g)(1) for the decommissioning record file.
 
Such documentation is important to provide a database for site characterization during
 
decommissioning, as well as, providing support for public and worker dose
 
assessments.
 
CONCLUSION
 
Although NRC regulations require licensees to make surveys, as necessary, to evaluate the
 
potential hazard of radioactive material released in order to assess doses to members of the
 
public and workers, the above examples indicate that undetected leakage to ground water from
 
facility structures, systems, or components can occur; resulting in unmonitored and unassessed
 
exposure pathways to members of the public.
 
===GENERIC IMPLICATIONS===
This information notice provides a timely means of communicating to licensee senior
 
management information regarding ground-water c
 
ontamination.  To address this important
 
issue, NRC is actively pursuing rulemaking to revise 10 CFR 20.1406, "minimization of
 
contamination," and its supporting guidance, as well as changes to NRC inspection and
 
enforcement guidance.  These ongoing NRC efforts are part of the NRC's Integrated
 
Decommissioning Improvements Plan (ADAMS
 
Accession No. ML050890059) to resolve issues
 
described in SECY-03-0069, "Results of the License Termination Rule Analysis" and its staff
 
requirements (ADAMS Accession Nos. ML030840302 and ML033210595).  A publically
 
available NRC memorandum dated September 23, 2005, provides the results of an initial NRC
 
study of ground-water contamination at decommissioning sites (ADAMS Accession No.
 
ML052630421).
 
==CONTACT==
This information notice requires no specific action or written response.  If there are any questions about this notice, contact one of the persons listed below or the appropriate project
 
manager in the Office of Nuclear Reactor Regulation (NRR) or Office of Nuclear Material Safety
 
and Safeguards./RA//RA/Charles L. Miller, DirectorHo K. Nieh, Acting DirectorDivision of Industrial and Medical Nuclear SafetyDivision of Policy and Rulemaking
 
Office of Nuclear Material SafetyOffice of Nuclear Reactor Regulation
 
and Safeguards
 
Technical Contacts: Timothy Frye, NRRMarvin Mendonca, NRR301-415-9676301-415-2191
 
E-mail: tjf@nrc.gov
 
E-mail:  mmm@nrc.gov
 
John White , RIJames Shepherd, NMSS610-337-5114301-415-6712
 
E-mail: jrw1@nrc.gov
 
E-mail: jcs2@nrc.gov
 
Steve Orth, RIIIThomas Nicholson, RES630-829-9827301-415-6268
 
E-mail: sko@nrc.gov
 
E-mail: tjn@nrc.gov
 
===Ronald Nimitz, RI===
610-337-5267
 
E-mail: rln@nrc.gov
 
ML030840302 and ML033210595).  A publically
 
available NRC memorandum dated September 23, 2005, provides the results of an initial NRC
 
study of ground-water contamination at decommissioning sites (ADAMS Accession No.
 
ML052630421).
 
==CONTACT==
This information notice requires no specific action or written response.  If there are any
 
questions about this notice, contact one of the persons listed below or the appropriate project
 
manager in the Office of Nuclear Reactor Regulation (NRR) or Office of Nuclear Material Safety
 
and Safeguards.RA//RA/Charles L. Miller, DirectorHo K. Nieh, Acting DirectorDivision of Industrial and Medical Nuclear SafetyDivision of Policy and Rulemaking
 
Office of Nuclear Material SafetyOffice of Nuclear Reactor Regulation
 
and Safeguards
 
Technical Contacts: Timothy Frye, NRRMarvin Mendonca, NRRJohn White , RI301-415-9676301-415-2191610-337-5114
 
E-mail: tjf@nrc.gov
 
E-mail:  mmm@nrc.gov
 
E-mail: jrw1@nrc.govJames Shepherd, NMSSSteve Orth, RIIIThomas Nicholson, RES301-415-6712630-829-9827301-415-6268
 
E-mail: jcs2@nrc.gov E-mail: sko@nrc.gov
 
E-mail: tjn@nrc.gov
 
===Ronald Nimitz, RI===
610-337-5267
 
E-mail: rln@nrc.gov
 
===DISTRIBUTION===
:  IN FileADAMS ACCESSION NUMBER:  ML060540038OFFICEIHPB:DIRSTech EdBC:IHPB:DIRSD:DIRSNAMESGarryHChangTFryeMCase
 
DATE06/14/200603/01/200606/14/200606/15/2006OFFICEBC:PRTA:DPRRDS:DWM:NMSSDRS:RIDRS:RIIINAMEBThomasCCraigJWhiteSOrth
 
DATE06/19/200606/21/200606/16/200606/16/2006OFFICELA:PGCB:DPRFCSS:UPSDPR:PGCBBC:PGCB:DPRNAMECHawesSCohenDBeaulieuCJackson
 
DATE06/26/200606/16/200606/28/200607/05/2006OFFICED:DIMNSDFERR:RESD:DPR (A)NAMECMillerNChokshiHNieh
 
DATE06/20/200606/19/200607/10/2006}}
 
{{Information notice-Nav}}

Latest revision as of 16:08, 10 February 2019

Redirect to:

Retrieved from "https://kanterella.com/w/index.php?title=Information_Notice_2006-13,_Ground-Water_Contamination_Due_to_Undetected_Leakage_of_Radioactive_Water&oldid=1329689"