ML20238F765

Rept of NRC Review Group Re Maxey Flats,Ky Commercial Radwaste Burial Ground

ML20238F765
Person / Time
Issue date:	07/07/1975
From:	NRC
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Shared Package
ML20238F347	List: IA-87-235, Provides Summary of 760203-06 Insps at Commercial Waste Burial Facilities in Sheffield,Il,Beatty,Nv,Richland,Wa, Maxey Flats,Ky,Barnwell,Sc & West Valley,Ny.Nrc Finds No Evidence of Significant Radwaste Migration.Related Encls ML20238F345 ML20238F384 ML20238F401 ML20238F411 ML20238F418 ML20238F526 ML20238F646 ML20238F695 ML20238F731 ML20238F741 ML20238F765 ML20238F842 ML20239A005 ML20239A021 ML20239A061
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FOIA-87-235 NUDOCS 8709160333
Download: ML20238F765 (18)

Text

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.. ... - REPORT OF THE ,

NUCLEAR REGULATORY COMMISSION REVIEW GROUP

, i REGARDING MAXEY FLATS, KENTUCKY

, COMMERCIAL RAI)ICACTI,VE WASTE BURIAL GROUND JULY 7, 1975 a

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Table of Contents I Page

. I. Introduction....... .........'.......................

1 II. Radiological Assessment...........,.................. 2

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1.11. Hydrological Assessment............................. 3 l

IV. Recommendations..................................... 5

- a Appendix A List of NRC Review Group Members... ....... .A-1 Appendix B Action Being Taken by the Commonwealth.h of l Kentucky Regarding Implementation of Recommendations as Set Forth in the Six-Month Study Report........................., B-1 l Appendix C Action Being Taken by the Nuclear Engineering Company, Inc...................  ;-l j

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Report of Nucle,ar Regulatory Commission Review Group

• _ s j Regarding

't Maxey Flats, Kentucky Commercial

, Radioactive Waste Burial Ground I. Introduction ,

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The commercial radioactive waste burial ground at Maxey Flats, Kentucky began operation 'in 1963 'under a license issued by" the s Commonwealth o.f Kentucky (Kentucky is an Agreement State) to Nuclear Engineering Co., operator of the site. The burial ground and adjacent area,,is owped by the Commonwealth of Kentucky. The State j

and the' licensee have conducted environmental monitoring programs on and around the site since prior to start up of operations. As a result of increasing quantities of radioactive material being disposed of at the site, State concern over water management at the site, and some indications of radioactivity being contributed to l

the Maxey Flats' site area as a result of site operations, the State initiated a special environmental monitoring study in November 1973.

The study covered a six-month period, ending in May 1974, and a project report of the s'tddy was' published'in December 1974. The general conclusion of the report was that site operations were contributing radioactivity to the environment, that the activity

, did not ersate a public health hazard, and there was a need to intensify monitoring activities to determine the long term signi-ficance of the findings.

As a result of the State's six-month' study report, there has been public interest regarding the health and safety aspects of the site. Kentucky Governor Julian M. Carroll requested the NRC, by TWX of April 30, 1975, to independently assess the situation and provide him with its findings and recommendations. Governor Carroll was informed that NRC would review recent information developed about conditions at the site, conduct a site visit and advise him of our findings. The Director, Office of Nuclear Material Safety and Safeguards appointed an NRC review group which consisted of members of the Agreements and Exp, orts Branch knowledgeable 'in i Agreement State relationships, and persons with expertise in hydrology  !

and radiological assessment from the Division of Technical Review, l Office of Nuclear Reactor Regulation. Appendix A lists members of the NRC review group.

The review g*nup examined information regarding the site, the State license, hydro-geological information about the site, the State's December 1974 project repo.rt, and the report of the State's Environ-

, , , , , mental Study Design Committee which was established in. February

' ', '1975'. On June 3, 1975, the review group made an unannounced visit

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.j to the burial ground in the' accompaniment of Mr. Charles Hardin, j Manager, Radiation Control Branch, Department for Human Resources, ,

Commonwealth of Kentucky. The review group met with Mr. Hardin and 1

- his staff on June 4, 1975, to review environmental monitoring data generated by the, State for the period since the,six-month study, i.e., through April 8, 1975, and to discuss the current actions being taken by the State. Appendix B reviews,the actions of the State concerning implementation of the recommendations contained in -

the six-month study report. It is,our coaclusion that the State is taking appropriate action in implementation of these recommendations. l Mr. G. Wayne Kerr, Chairman of the review group, briefed members of l Governor Cir' roll's staff on June 4 regarding the group's activities.

I On June 5, 1975, the group met with NECO representatives to receive i their views on environmental monitoring results, operation of the j

evaporator at the site, current operating practices and the status l of the water management program. Appendix C reviews the actions i being taken by the company.

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Mr. Kerr discussed the review group's activities with Ms. Jackie l

Swigart, Chairperson,' Rentucky Environmental Quality Commission on l June 9, 1975. Ms. Swigart had expressed the Commission's concern i about the burial site in a letter dated April 21, 1975, to Governor Carroll.

l II. Radiological Assessment As a result of the site visit and evaluation of the data available

, with regard to aquatic and atmospheric releases of radioactive material during FY 1975, quantitative estimat.s of environmental impact as well as recommendations with respect to operation of the facility (which are' discussed in Section IV), were developed.

A. Aquatic Releases -

The environmental data reviewed indicate that tritium, beta-l active and alpha-active materials are being released in the hydrosphere in unrestricted'd areas. In our evaluation it was assumed, conservatively, that the water would be consumed by man all year long at the conventional rate of 2.2 liters per

) . day. Using the maximum concentrations identifed at certain l sampling stations in the unrestricted areas, the maximum l potential tritium whole body dose was calculated to be

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15 mrem per year. For beta and alpha activity, including natural radioactivity, the potential doses would not exceed 4

110 mrem per year t'o the whole body and 1500 mrem per year to the skeleton (using Sr 90 as the limiting beta emitter and

' -* - e Pu239 as the limiting alphe emitter). These doses do not e

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V represent actual hun.an exposures. They are based on the maximum levels of radioactivity observed in the environment l

. and the most restrictive radionuclides mixture. Actual human I doses would be below these levels. ,

1 B. Atmospheric Releases , i

~ 1 l The potential radiation dose from the evaporator effluent was '

l estimated at the location of the nearest residence, about 0.5  ;

mile north of the site. The major component of the radioactive l releas'~s',

e a~s " expected, was tritium. This was calculated to I provide a potential dose at the nearest residence which would l not exceed 5 mrem per year. In addition, traces of other l

< nuclides are known to be pres'nt e of which the largest exposure is that due to Sr90 For this nuclide the calculated poten- l tial bone dose would not exceed 1.5 mrem per year.

C. Conclusions -

i . We conclude that, at th,e present time, there appears to be no l significant public health problem associated with the release of radioactive material from this burial site. The Radiation a

, Control Branch of the Department for Human Resources of the Commonwealth of Kentucky has adequstely evaluated the potential

. effects to the public health and safety through its environ- ,

mental monitoring program and is continuing this program in

. order to detect any problems that mighc arise in the future. l Recommendations to be considered by the State concerning their )

environmental monitoring program are contained in Section IV j of this report.' Of special significance is the need for additional isotopic analyses of radiological samples. These i are necessary to distinguish between the natural radioactive i environment and that material which is being released from the site. By doing the above, the actual potential human exposure can be better estimated. Also, the analyses can serve as bases for the measurement 6f radioactive material migration. ]

Notwithstanding the above, the data on tritium concentrations

. in the water sampled from Test Wells 11 8 (located onsite but in the unrestricted area) and 13 E (onsite and in the restricted j area) are sufficiently high to merit consideration of further action. This is addressed in R' commendation e No. A.6.  !

5 III. Hydrological Assessment

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'A. Site Description and Operations '

The site is on a relatively flat hilltop in north central Kentucky. Most precipitation (annual average of about 47 inches) that falls on the site runs off and into small streams. i l

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,{ Precipitation'that does not run off is either evaporated,

'Y consumed by vegetation or percolates into the ground. The l

, fraction that percolates flows at a low rate into underground l zones for eventual drainage to seeps, wells and stream channels. l 1

1 The subs,urface material is' composed of succe'ssive layers of I different shales.and s

sandstone. The surficial layer is clay, ,

a weathered shale. Groundwater is considered to move through ,

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Although,the radioactivity detected in the offsite environ-ment presents no significant health problem so the population residing in the area, removal of water from th'e trenches is necessary to minimize the potential for the migration of radioactivity. The licensee has performed a considerable amount of work to reduce the infiltration of surface water into completed trenches in the older section of the burial facility. This work includes grading and improving surface drainage, recapping of trenches with clay, and establishing a vegetative ground'c~over over the' capped trenches. Improved methods are currently being used in the completion of newer trenches to minimize the infiltration of surface water into

, the trenches. We believe these methods are necessary to minimize the infiltration of water ,into completed trenches.

It is not possible to assess the complete effectiveness of these efforts at the present time.

. - The State requires the licensee to remove water from open trenches and to remove liquids collecting in closed trenches.

The licensee has established a program to pump water from the trenches until the trenches reach a dry status as defined in the license. The licensee has installed an evaporator system to treat and process liquids removed frod the trenches. The liquids are first pumped to a temporary liquid storage area adjacent to the old burial arca and subsequently processed through the evaporator. We helieve these actions are appropriate in order to minimize the mo'vement of contaminated water from the trenches to the underlying geo. logic formations.

The temporary liquid waste storage area consists of steel tanks having a total capacity of about 600,000 gallons. The storage area is surrounded by a berm or dike approximate'ly four feet high. At~the present time about 500,000 gallons of

, liquid waste is stored in this area. An apparent deliberate

',act by a person or persons unknown last winter resulted in the contents of one of these tanks being dumped within the bers area. Consequently, all rainfall which is collected within a the area must now be treated as radioactive liquid waste. All

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rainfall collected within the area is now being transferred to -

a newly lined pond. Leakage from the pond and dilution by additional rainfall is minimized by confining the contaminated liquid between two impermeable membranes. There are two additional onsite ponds: one is used as a non-potable water supply and the other is a surface drainage pond. The licensee's efforts to minimize the quantities of wa'ter stored on site .

should be continued. It appears that the problem of migrati'on '

of radioactivity at the site can best be controlled by further improving surface and. groundwater management techniques at the site. -- -

B. Conclusions After visiting the site and reviewing data collected by the

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Commonwealth of Kentucky, the Nuclear Engineering Company and various federal agencies, we conclude tha,t to date the wastes are being entombed at the site and in an environment containing

, significant amounts.of gro,undwater. The continuous use of the groundwater evaporator has, in our opinion, substantial,1y reduced the offsite mig /ation of contaminated water. Actions should be taken to improve the water management program, a

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minimize the need for the evaporator, and forther reduce offsite migration of lov level radioactive water. Recommended measures to accomplish these objectives are set forth in Section IV of this report. ,

IV. Recommendations The following recommendations address several methods which should be considered by the State to improve water management and site operations. Improved water management should minimize the potential for migration of radioactivity from the burial trcaches. Each should be evaluated on a cost effective basis. The, specific recommendations in A below relate to,immediate improvements and should be considered by the State for implementation in the near term. The general recommendations in B below address additional measures which could

, be considered if the water management aspects of site operations do

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not improve. These should also be considered in lieu of or in conjunction with the proposed studies of the Environmental Study Design Committee, i.e., if conditions at the site do not improve and the monitoring programs indicate increasing levels of environmental radioactivity, further positive actions to improve the water management J program should be taken as opposed to only studying the site.

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A. Specific Recommendations for Consideration by the State

. 1. The height of tegetative. ground cover should be kept to a minimum. Long grass will hold the ralnfall and give it a longer period of time.to infiltrate, thos increasing the

_ amount of groundwater.

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2. The density of the top surface layers of soil chould be

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d e te'rmined. If it is not compacted to near cptimum levels (as determined by the standard American Association of State Highway Officials compaction methods), engineering methods should be used to obtain maximum compaction. If an optimum surficial density cannot be obtained, the surface could be covered with a well compacted layer of some essentially impervious material, such as clay or soil cement.

3. The method of measuring water extracted from the trenches, as defined in t-he licence, should be evaluated. Water extraction measurem,ents could be improved by requiring the measurements to be volumetric rather than by pumping rate. Consideration should also be given to pumping trenches more frequently at a lower rate than presently specified to minimize water aedumulations, contact with waste, and potential contamination of groundwater.

, 4. The effect of the onsite non-engineered ponas on the groundwater table should be evaluated. These ponds should be eliminated or lined unless it can be demonstrated that they do not significantly enhance dissolution of radioactive materials in the trenches and increase the rate of movement of contaminated groundwater.

5. The program for measuring source terbs (radioactivity being, released in the evaporator effluent and that present in trench water) and the environmental monitoring pro, gram being conducted by the licensee should be continued. The State should assess the licensee's program to be sure it j

includes nuclide analysis of evaporat'or effluent releases, trench water and appropriate environmental media (air, water, soil, cr'ps o and othet direct pathways to man).

An air sampler should be placed at the nearest residence 4

north of the site. The monitoring program should be.such

. . . - e that it is possible to evaluate the environmental impact

' from all significant pathways such as breathing, drinking water, eating fish, etc. It should provide information needed to determine whether public exposures are within established limits and to ensure that 1cas term buildup of

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{ specific radionuclides in. the environment will not become

.'f significant. The State may exercise its regulatory

. function to ensure quality assurance and compliance by splitting samples, spot checks, etc., or by carrying out an equivalent environmental monitoring, program.

6. With respegt to the results of tritium analyses of water samples taken from test well 11 E we believe the waste in.

Trench No. 31 containing about 650,000 curies of tritium is the most likely source. An assessment should be made of,the. feasibility of isolating this waste in place or removing and disposing of it in an appropriate manner.

Such an assessment should be performed on a cost-benefit basis including consider.ation of any additional radiation safety problems that may be created by such measures.

With* respect to the radioactivity data from test well 13 E, it appears that the most likely source is waste buried in Trench No. 33 L. This trench should be brought to a dry steth to ddtermine'if' tritium levels in well 13 E can be reduced. .

, B. General Recommendations for Considetstion by the State

1. Measures'could be taken to in' crease the ability to remove water from future trenches (once they are closed).

Originally the trenches were to have a gravel drain on the bottom. This practice was later discontinued because the backfill material was apparently clogging the gravel.

Clogging could be prevented if an adequate layer of sand was provided on top of the gravel. *

2. Lined channels could be provided between and around the capped trenches to speed the removal of runoff and thereby decrease the time available for rainfall to infiltrate into the soil. .

3. If the deep hydro-geological study proposed by the Environmental Study Design Committee is initia.ted, an attempt should be made to determine the extent of the pervious zone indicated by EMCON Borings 2E, 7E, 8E, 10E, and 12E. The zone should be located and its leakage investigated. The zone should be grouted with a suitable slurry material, such as clay, if g it can be determined that the zone contributes significantly

,- , , . ., to offsite groundwater flow. A similar technique could be used to seal any other leaky zones encountered as a

• M result of subsurface explorations. .

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4. The need for the proposed mantle study we tid be obviated

] by successful reductions in percolation. Subsurface exploration.s could also be used to estabitsh whether groundw'ater is reaching the site in the otar surface l strata by flowing from the north and nort:1 east. If it was determined that a .significant am.ount )f water is l reaching the site in this manner, an inte rceptor ditch l could be constructed across the north end of the site. , ,

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S. Consideration could be giv'en to effectively encapsulating buried waste in an impervious side and b:: tom trench liner.

Such a -liner could be constructed of bent anite, hydraulic asphalt or other durable imper:vious mate La1. Because of the manner in which waste is dispost.d af, such a liner

, would have to be constructed in sections along a trench.

C. Summary i A number of proposals for investigating E.he Mixey Flats site

! , have been made. While studies' for learning n ire about site l

conditions have merit, we believe careful cor sideration of j positive actions to reduce offsite migration of contaminated {

water should be considered. J

' b If conditions at the site do not improve and the monitoring l, programs indicate increasing levels of envitanmental radio- 1 activity sufficient to be of public health oncern, contingency j actions should be instituted. State and liaensee efforts to

~ develop a contingency plan should be contiraed in the event corrective action is deemed necessary base'. upon the results of the environmental monitoring program.  !

The State has requested that NRC contribLte to the costs of  !

the studies recommended by the Environmental Study Design Committee. The review group considered this matter from a technical standpoint and believes that :he information expected  !

to be obtained from the recommended stidies will be sufficiently '

site specific so as not to be of direc; appl 1cability to other l l , NRC activities. Therefore, the review 0 group does not recommend

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that NRC provide financial assistance to fhe studies.

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- . APPENDIX A -

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I NRC REVIEW GROUP MEMBERS

. . s G. Wayne Kerr, Chief (Chairc.an)

• l . Agreements & Exports Branc!:

Division of Materials & Fuel Cycle . . 1 Facility Licensing . ' '

I Office of Nuclear Material Safety and Safeguards k'.1111am Gammill,- Chief-Site Analysis Branch Division of Technical Review Office of Nuclear Reactor Regulation Jacob Kastner, Chief l

Radiological Assessment Branch ,

., Division of Technical Review -

l Office of Nuclear Reactor. Regulation .

L. G. Hulman

• Site Analysis Branch j G. P. Turi . -

Site Analysis Branch J. S. Bland Radiological Assessment Branch P. H. Lchaus Agreements and Exports Branch e

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AFFENDIX B t

Action _Bying Taken by t_he Commonwealth of Bntucky Regarding Impl emer--

,' tation pf Re, commendations .g_ Set Fcrth in the Six Monah StufdL eport._

R A. On January 7, 1975, the S*; ate informed the Nuclear Engineering Co.

(NECO), the' site operator, of the results of the State'v. sit-month, -

study. Their letter stated that cc,nclusions drawn from tha study indicate the :,f te is contributing radioactivity to the environment.

They req"ested NECO to notify them of the steps NECO is taking an::

future actions to be taken to assure that the site d:es not co.ttjbute further significant radioactivity to the cavironment. The JECO response consisced of a report cd tneir environmentri study comnittee.

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The primary conclusions of the report are:

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1. No long term increasing trends in environmental radioactivity are observable f rom NECO's environmental moni toring dais.

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2. The preeent extensive environmental monitoring prog;am sbauld be continued for two years after all trenches reach a d y statua. ,

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' No physical remedial' anti.ons are planned untii the monitoring program ment iened in No. 2 is completed. (NECO plans to decide.

on what physical remediaE actions should be taker. based on an analysis of data gathered through the monitoring progsam.

NECO does not fully afr.te with tbo conclusions drawn from the State's study, particularly since they believe their data, covericq a longer period of t,ime than the six-month study, shows tio trends touard inc,reasing levels of environmental radioactivity However, the Company has agreed during discussions that the State data indicates the site is contributing small quantities of radioactivity to the offsite environment as any nuclear fagility world. They believe the problem. lies in how the data is interpreted, and they believe neither the State's datu r.or their data shov eny real potential for human exposute to persons 1.dving in the t.rea.

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The State expanded their Radfeactive Waste Disposal Eavironaental l

1 Study Design Committee to include representative from the:

U. S. Geological Survey Kentucky Geologicsl Suncy J Nuclear Regulatory Cemmissien

. , - c Environmental Protection Ag ncy Energy Research and Development Administration M

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. Kentucky Science and Technology Commission 1 .y; .

Kentucky Department for Natural Resources and Environmental l

Protection

.' -Kentucky Department for Human Resources The Committee met en February 18-20, 1975, and developed a six point program.to be considered for further studies ,at the site as listed

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1. Deep Hydro-Geological Study

2. Surface Run-Off Water

3. Mdurl'e Study (Weathered Zone) a 4. Definition of Source Term 5- Agricultural Pathway

6. Environmental Biological Pathway i

The State is proceeding in the implementation of these studies and has requested financial us.sistance from several federal agencies includigg the MRC, Presently, the EPA is conducting the Agricultural Pathway study at no cost to the State. NECO, with some State participation, is conduct 16,g the Curface Run-Off Water study. The Departmeat of Human Resources staff has recommended that the Environ-mental Biological Pathway study be initiated. The State plans to

, take no action regarding the other studies until they receive a response to their request for financial assistance from the federal agencies.

. , C. The State has continued to expand its comprehensive environmental nonitoring program at the site. Prior to the six-month study the State was sampling 12 stations for water at a monthly frequency.

The program has been expanded to include 30 sampling stations which are sampled on a bi-weekly basis. In addition, the State and NECO have established a split sampling program and certain samples are also analyzed by the EPA. The results of the split and tri-sampling programs arc in substantial agreement. . .

D. The State is proceeding with amendment of NECO's license to require improved site operating procedures, burial. containment, and environ-mental monitoring by NECO. The license is presently being renewed and amended in its entirety. The primary changes proposed to be made in the license are:

1. Improved trench construction cnd completion including the placement of three sumps in each trench recessed into the 4

trench wall to prevent shear. ,

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\ 2. Improved method for keeping water off the active face of l  !

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3. The containment of tritium. contaminated waste in ceramic material when the specific activity exceeds 10 microcuries l . per milliliter'and buried such that the container will not l

be breeched. .

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4. Restriction on the stack' effluent from the evaporator to (

reduce the contribution of radioactivity to the environment'.

5. Cont'inuation of water management program. The State has renegotiated the agreement between the State and NECO l

• which provides that NECO will supply a security in the amount of $430,000.00 to assure that NECO carries out the water management program as specified in NECO's " Plan of Corrective Action and Schedule of Compliance" previously

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filed with the State and incorporated into NEC0's license.

The money will go to the State if NECO fails to carry out the program. The agreement was signed on March 19, 1975, has no expiration' date, and will not expire until all trenches reach a dry status as defined by the license.

E. The State has requested and has obtained the opinions of two federal agencies relating to the appropriateness of applying a more restrictive criteria than the Maximum Permissible Concentrations (MPC's) as specified in the Kentucky Radiation Regulations to the potential mi'gration of radioactivity from shallow land radioactive waste disposal facilities. Both EPA and NRC indicated that the philosophy of total containment should be applied to the burial of radioactive l waste and the design' objective of a site should be such that all l waste is retained within the site boundaries,throughout its hazardous l lifetime. The NRC stated that the MPC's and "as low as practicable"

. concept are not appropriate for application to the migration of radioactive waste f. rom a burial site except 'that the MPC values are appropriate in assessing the publ16 health significance of the radioactivity detected.

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F. The Kentucky Science and Technology Commis'sich has appointed a task group to study, evaluate, and determine the changes which may be needed in the perpetual care and long range maintenance program for the site and the associated financial responsibilities for carrying out the program.

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. N C-1 APPENDIX C i q

. 1 Action Being Taken by the Nuclear Engineering Company, Inc. (NECO)

Several actions are listed below which NICO has taken to improve conditions at the site. Several of these were initiated prior to the six month i study performed by the State. -

! A. NECO appointed a three member inter.nal task group to study the State's andthe Company's environmental data. The Task Group l l

i prepared a report which was submitted to the State in response to l the State's'1/7773 letter. (See Item A in Appendix B.)  !

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, l l B. KECO has conducted a surface run-off study. The report of their l study is being prepared for transmittal to the State. They found I several surface areas onsite which were contaminated and cleanup ,

I work on these areas was started in March.1975. The State partic- I

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ipated in a part of this study and believes.the drop in levels at l certain sampling stations is attributable to the cleanup operations 1 being undertaken by NEGO. - -

C. NECO,has increased their own environmental monitoring program to l coincide with'that being conducted by the State. They are partic-I ', ipating in a split sampling program with the State and have obtained better onsite laboratory instrumentation'n capability for sample analyses. ,

D. NECO proposed to the State that future burials of tritium, which exceed a specific activity of 10 microcuries per milliliter, be contained in ceramic material. 'The State plans to incorporate this condition into the license with the additional condition that the container be buried such that the container will not be breeched.

E. NECO believes all phases of the operation have improved and cited the following examples: - '

1. New management and site opbrations personnel have been hired. I The operation of the site has received increased management  ;

attention. Quarterly meetings and unannounced inspections of j the site and operations are conducted by management with site i 1

operations personnel.

2. Improvement in the surface water management program through 1 j

better control of surface water run-off, grading resealing  ;

d (capping) of existing trenches and the establishment of a  !

'i. v . r vegetation cover on these trenches.

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3. The conduct bf an extensive water management program to remove

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water from the trenches. An svaporator system has been installed

• to reduce the radioactivity and concentrate the liquids pumped

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4. Increased attention to site operations and'the^ materials received from customers for burial. A.new form f'or use by

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customers in' reporting the material being shipped for. burial ,

has been developed.

5. The conduct of hydro-geological evaluations of the site and based on these evaluations development of a master site development plan and a. revised radiation safety plan for site ]

operations. Thase involve new methods for preparing and utilizing trenches, the installation of three sumps per trench recessed into the trench wall, improved capping procedures, and methods for keeping water off the open face of waste in the trench. .. . l

. 6. Twenty-four of the 42 completed trenches have bten brought to a dry status as defined by the license.

I. Efforts are being made to reduce: 1) the quantity of water stored at the tank farm which subsequently is processed through j the evaporator; and 2) the size of'the tank farm. i 9

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N.WE AGENCY ADDRESS 6 Pil0NE Charles Herdin Ky. Department for 275 East Main lluman Resources Frankfort , Ky. 40601 502/564-3700 Gerald H. Daly Chief, Cperations Branch Washington, D.C.20545 Div. of Waste Management 5 yny Transportation gg 9 73 Encrgy Research 6 Develop.

Administration Al-3209 CXXI G. Kayne Kerr Chief, Agreements 5E$portsBr. Washington, D. C. 20555 Div. of Materials and Fuel Cycle 301/492-7767 Facility Licensing Nucicar Regulatory Cc:nn.

l U. S.,

liarold H. Zehner Hydrologist, U.S. Geological 502/582-5241 Survey Room 572 Federal Bldg.,

Louisville, Ky.

Hans C1aassen U.S. Geologic.1 Survey Denver, Colorado l Bldg. 25, Denver Federal Ctr. 303/234-2115 Denver, Colorado S0225 David T. Clark Ky. Dept. for IL=an Resources 275 East Main Radiation 6 Product Safety Br. Frankfort , Kentucky 405C 502/564-3700 George D. DeBuchananne Chief, Office of Radiohydrology Reston, Virginia 220S2 U. S. Ccological Survey 703/E60-0976 Stop 432 Reston, Virginia 220S2 David C. Bayha Geologist 6 Head Nater Section Lexington, Kentucky 405L Kentucky Geological Survey 606/25S-SD79

.307 Mineral Industrics P,uildi.ng 120 Craham Avenue, University of Ky.

Art Curtis Kentucky Dept. for Natural Resources Frankfort, Ky.

6 Environmental Protection 502/564-7030 Capital Plaza Tcwcr 6th Floor Kurt Itthtanen Chemist, Ky. Dept. for ik=an Resources 275 E. Main Street Radiation 5 Product Safety Branch Frank fo r t , ,Kr. 4 0001 502/ E,M -3700 Richard M., Fry Ky. Dept. for ihrnan Resources Frank fort , Ky. 40501 I Asst. Director, Office of Const:ncr 502/564-3700 Health Protecticn 275 E. Main Street

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'o NN4E AGENCi' ADDRESS 6 Pl!ONE i l

Damon W. Ilarrison Kentucky Science G Technology Comn. Frankfort, Ky. 40601 State Planning Comittec 502/564-3450 Room 157, S. tate Capitol llarry Kolde U.S. EPA, R G NEF Cincinnati, Ohio 4526S Radiochemistry G Nuclear Engineering Facility G. Lewis Meyer Office of Radiation Programs (AW-559) Washington, D.C. 20460 Hydrologist U. S. Environmental Protection Agency 202/755-4863 401 "M" Street, S.W.

Mike H. Roulier Soil Scientist EPA Solid G Hazardous Kaste Cinciinw' i , Ohio 4526S Research Laboratory 513/6S.' 4487 National EnvironT.cntal Research Ctr.

Charles F. Eason Nuclear Engineering Co., Inc. Washington, D.C. 2005C l Suite 1000 202/785-4705 l 1100 - 17th Street, N.W.

John A. McCabe U.S. Geological Survey . Louisville, Ky. 40202 l 572 Federal Bldg. 502/582-5241 l 600 Federal Place j Louis A. Krumhol: Water Resources Laboratory Louisville, Ky. 4020E University of Louisville 502/636-42S0

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James !!. Leonard Nuclear Engineering Co., Inc. Louisville, Ky. 40207 P.O. Box 7246 502/491-S300 4

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Ilydrologic Investigation of Unsaturated Zonc of

, Maxey Flats h'aste Disposal Site l

Objectives

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1. Determine the water movement patterns in the un-saturated conc of the flaxey Flats waste disposal site.

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2. Develop a model capable of predicting the move-1 1

• I ment of water from a waste cell in the event of various degrees of flooding in the cell.

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3. Develop a model capable of predicting the effects l of various types of rainfall events on the move-1 mont of water in the unsaturated =cne of the ::a:.:ey Flats waste disposal sito including the possibil-ity of cell flooding.

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• The unsaturated conc is taken to be 50 foot in donth l or the depth to a regional water table whichever 'is less. .

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. Objective 1 I

l A network of neutron access tubes vill be installed throughout the site. This network uill consist of 50 tubos each runninc-50 ft. in doeth. .- As the tubes arc installed Shelbv - tubo core sampics vill be obtained. A core sample will be tahon during 4

each 5 ft. increment of do.eth for a total of 10 sam. oles .ocr l

. access tube location. The sampics vill be used to estimate the 1

water characteristic curve (relation between water content and i pressure head) and the unsaturated hydraulic conductivity as a function of pressure head.

inch access tube will be monitored at least wochly uith a nou-tron moisture cac.o - to determino the vater content profile at ud -, u. _o m.n u..t.o ..

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enabic a determination to be made of c::isting tator movement 1 patterns. To maho those dorcrainations in vill be necessary to develoo a s.occial com.outor nrocram.

., - This oroc. ram will be uritten 1

so that an estimate of the vertical deep percolation and of the  !

lateral unsaturated movement of water frcm the site can bc mado.

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.1 A number of infiltronctor tests will be made throughout the cito to c.c:ine the water inta.c n caoacity o_, the site. O tn.er ava,ro_oc.ic coasurcnonts will include rainfall at 3 locations and runoff at 3 locations. The data will enable a reasonably accurate dctor- l r

, mination of the cuantitics of water ontoring the unsaturated zonc. The soil water profile measuromonts will permit an esti-mate of the change of water content in the unsaturated conc.

The difference in the unter entering the conc and the chanco -

in water content of the conc will permit an estimate to be mado I

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Objcetivo 2 A tuo dimensional modc1 of unsaturated-saturated water novoment

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in typical cross scetions of the waste disposal sito will be de-veloped. This model will considor horizontal and vertical water movement in a planc.

The model vill be capable of predicting the effcets of various degrecs of flooding in a waste cell on water novament from that cell and cell to cell movement of water.

A typical cross scetion is shown in figure 1. By varying the boundary conditions of the cross section, expceted water movement patterns in the section can be simulated. For exanplc if cell A beconcs flooded to some depth, the expected resulting movement of this water can oc determined. The degree of diooding of adjacent eclls and the rate of water movemen; away fren the i

.e coc.cc col _3 can be estimatca.

, . i Such a model will involve numerical solutions of the non-linear partial difforontial equation governing tuo dimensional unse. u-rated vator movcacnt for various boundary conditions. Also, it will be possibic to consider certain types of he:crogenci:ics in the upper soil regimos. Such solutions require the use of a digital computcr.

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w 5-Objective 3 The two dimensional model developed under objectivo 2 will be used to study the effect of scvoro rainstorms on the subsecuent movencnt of water into the upper profile of the .tasto disposal site. The possibility of wasto cell flooding, the degree of flood-ina and the resultinc.> =cvement of water from the flooded cc11s w:11 ce exam nce.

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1. .:1uch of the data collected under objective 1 wi ll be re-

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quired as model parameters in objectivos 2 and 3.

The depth of the unsaturated conc can be defined to be any l

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t depth as desired. IIoweve r , increasing the. depth uill pro-portionately increase the project costs since additional sampling, drillin and ant. lysis will be required.

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3. A three di=cnsional codel of unsaturated flow in the entire

cxcy I'lats site capable of describing unsaturated flow in The roi: ort b" ?a.cado.culos detail is not feasibic at this ti=c. .

and 5:inograd (1974) states that one dimensional modeling of unsaturated flow is feasible. ~7c' fac1 we can dovc1cp a t'.co dimensional codel. A two dimensional model will be rec.uired to describe the lateral unsaturated movc=cnt.

4. ?roject duration - 3 years.

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. 4 Proposed Budget (Annual)

I. Salaries and Wagcc Technician 9000 Roscarch Associato 15000 Haan and McIls 6000 i Sect. 500 Labor 6800 i

37300 II. Overhead 55% of S&W 20315 4

III. Cor.puter 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> 0 360 3600 IV. Travel 30'20 t.

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Total Annual $69,415 t

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Additional First Year Budget

'I . Exploration and Sampics Installation of Neutron Access Tubes 15800 Shelby Tube Samples 15800 ]

Tubos 3160 l l

Tubo plugs and end caps 225 l 1

34985 i

II. Neutron .' actors l 1

Depth Density ,

4230 Surfaco 3775 i 4

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1 III. Soil :'oisture Equipment 3000 IV. Hydrologic Equip =cnt 1- ~

l h'ator level recorders 900 Flunos 1095 I l '

l . Raingauges 1000 1

2395 V. Misc. .

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Total S51,955 1.

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Budget Su r.ary l i

Year 1 $121,400 l 1

2 69,415 l 1

4 3 69,415 i S260,230 1

I Salarico and wages 111,900 i Overhead 61,545 Computer ,

10,000 Travel 9,000 Current Expense 15,000 Equipment 17,000

, Drilling, Tubo installation  !

and Sc=plc collection 34,935

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I JUL 141975  ;

r Mr. C. Leslie Dawson The Secretary for Human Resources Connonwealth of Kantucky Frankfort, Kentucky 40601 1

Dear Mr. Dawson:

In our June 25, 1975, response to your May 13, 1975, letter, we informed

, you of our activities regarding review of the Maxey Flats low level i radioactive waste disposal site which included consideration of your request for financial assistance to conduct further studies at the sito.

While we are able to provide continuing technical assistance to the State, we are not able to provide financial assistance. We believe that t

the information expected to be obtained from the Environmental Study Design Cossaittee's proposed studies will be sufficiently site specific so as not to be -of direct applicability to other NRC activitie.s.

l Enclosed is the report of the NRC review group which we have sent to Governor Carroll. The report concludes that there is no significant public health problem associated with the release of radioactive material from this burial site. It is also our conclusion that.the State has been taking appropriate action concerning implementation of the recommendations

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as contained in the six-month study report. The report includes several reconnendations for consideration by the State which deal principally with

_ methods for improving water management at the site so as to minimize l migration of radioactive material. I Regarding the statements i'n your letter that the AEC concurred in your issuance of the license for the Maxey Flats burial ground in 1963, information in our files shows that while the AEC staff commented upon certain geo-hydrological aspects of the site that abould be investigated, the AEC never actually reviewed or concurred in all the information upon which the original licensing action was based. This was considered

" appropriate since Kentucky was an Agreement State with authority to regulate, among other things, commercial burial of certain radioactive waste in the State.

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.Mr. C.LLeslie Dawson

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,. .4 If you have' any questions regarding the'attachhd report and its recommendations, please let me know.

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.. .' Sincerely,  !

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1 c ~ Odginal signed by , ,

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.. Kenneth R. Chaptnan _

Kenneth R. Chapman, Director Office of Nuclear Material Safety

. . 3, . and Safeguards E'nclosure:

- Report of HRC Review Group.

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, Distribution: w/o enclosure l SECY 75-2746 (3) l KRChapman RECunningham -e

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DANussbaumer .. e GWKerr PHLohaus GErtter.(EDO 8751) .

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DAN' sbaumer RECun 'hgi$am K p1Ea' v .

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t REPORT OF THE NUCLEAR REGULATORY COMMISSION REVIEW GROUP REGARDING MAXEY FLATS, KENTUCKY COMMERCIAL RADI0 ACTIVE WASTE BURIAL GROUND JULY 7, 1975

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Table of Contents I Page I.

Introduction........................................ 1 II.

Radiological Assessment....... ................,..... 2 III. Hydrological Assessment...........'.................. 3-IV. Recommendations.. .................................. 5

, Appendix A List of NRC Review Group Members........... A-1 Appendix B Action Being Takan by the Commonwealth of Kentucky Regarding Implementation of l

Recommendations as Set Forth in the Six i i

1 Month Study Report......................... B-1 Appendix C Action Being Taken by the Nuclear Engineering Company, Inc................... C-1

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• Report of Nuclear Regulatory Commission Review Group l Regarding Maxey Flats, Kentucky Commercial l Radioactive Waste Burial Ground I. Introduction l l

The commercial radioactive waste burial ground at Maxey Flats, i Kentucky began operation in 1963 under a license issued by the Commonwealth of Kentucky (Kentucky is an Agreement State) to Nuclear Engineering Co., operator of the sito. The burial ground and adjacent area is owned by the Commonwealth of Kentucky. The State and the licensee have conducted environmental monitoring programs on and around the site since prior to start up of operations. As a result of increasing quantities of radioactive material being disposed of at the site, State concern over water management at the  ;

site, and some indications of radioactivity being contributed to '

.the Maxey Flats site area as a result of site operations, the State initiated a special environmental monitoring study in November 1973.

The study covered a six month period, ending in May 1974, and a

project report of the study was published in December 1974. The

! general conclusion of the report was that site operations were l

) contributing radioactivity to the environment, that the activity  !

did not create a public health hazard, and there was a need to i intensify monitoring activities to determine the long term signi-ficance of the findings. ,

As a result of the State's six month study report, there has been public interest regarding the health and safety aspects of the site. Kentucky Governor Julian M. Carroll requested the NRC, by {

TWX of April 30, 1975, to independently assess the situation and {

provide him with its findings and recommendations. Governor Carroll I was informed that NRC would review recent information developed l about conditions at the site, conduct a site visit and advise him j of our findings. The Director, Office of Nucidar Material Safety and Safeguards appointed an NRC review group wh,1ch consisted of members of the Agreements and Exports Branch knowledgeable in Agreement State relationships, and persons with expertise in hydrology and radiological assessment from'the Division of Technical Review, i Office of Nuclear Reactor Regulation. ~ Appendix A lists members of l the NRC review group. r .

The review group examined information regarding the site, the State I license, hycts-geological information about the site, the State's i December 1974 project report, and the report of the State's Environ-  !

mental Study Design Commit. tee which was established in February i

. 1975. On June 3, 1975, the review group made an unannounced visit M .

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to the burial ground in the accompaniment of Mr. Charles Hardin, Manager, Radiation Control Branch, Department for Human Resources, Commonwealth of Kentucky. The review group met with Mr. Hardin and I his staff on June 4, 1975, to review environmental monitoring data generated by the State for the period since the six month study, i.e., through April 8, 1975, and to discuss the current actions being taken by the State. Appendix B reviews the actions of the State concerning implementation of the re~ commendations contained in l the six-month study report. It is our conclusion that the State is  !

l taking appropriate action in implementation of these recommendations. I Mr. G. Wayne Kerr, Chairman of the review group, briefed members of Governor Carroll's staff on June 4 regarding the group's activities.

On June 5, 1975, the group met with NECO representatives to receive their views on environmental ponitoring results, operation of the evaporator at the site, current operating practices and the status of the water management program. Appendix C reviews the actions j being taken by the company.

Mr. Kerr discussed the review group's activities with Ms. Jackie Swigart, Chairperson, Kentucky Environmental Quality Commission on June 9, 1975. Ms. Swigart had expressed the Commission's concern about the burial site in a letter dated April 21, 1975, to Governor Carroll.

l l II. Radiological Assessment As a result of the site visit and evaluation of the data'available with regard to aquatic and atmospheric releases of radioactive material during FY 1975, quantitative estimates of environmental impact as well as recommendations with respect to operation of the facility (which are discussed in Section IV), were developed.

l A. Aquatic Releases The environmental data reviewed indicate that tritium, beta-l active and' alpha-active materials are being relaased in the hydrosphere in unrestricted areas. In our evaluation it was assumed, conservatively, that the water would be consumed by l

man all year long at the conventional rate of 2.2 liters per l day. Using the maximum concentrations identifed at certain l sampling stations in the unrestricted areas, the maximum l potential tritium whole body dose was calculated to be 15 mrem per year. For beta and alpha activity, including l natural radioactivity, the potential doses would not exceed 110 mrem per year to the whole body and 1500 mrem per year to the skeleton (using Sr 90 as the limiting beta emitter and Pu239 as the limiting alpha emitter). These doses do not

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'- i j represent actual human' exposures. They are based on the y maximum levels of radioactivity'y observed in the environment and the most restrictive radionuclides mixture. Actual human doses would be below these levels.  ;

B. Atmospheric Releases '

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. The potential radiation dose from the eva'porator effluent was , -

estimated at the location of the nearest residence, about'0.5 I

l mile north of the site. The major component of the radioactive releases, as expected, was tritium- . This was calculated to provid'e-~a p~otential dose at the nearest residence which would not exceed 5 mrem per year. In addition, traces of other  ;

nuclides are known to be present of which the largest exposure  !

is that due to Sr90 For thi's nuclide the calculated poten- I tial bone dose would not exceed 1.5 mrem per year.

C. Conclusions We conclude that, at the present time, there appears to be no  ;

significant public health problem associated,with the release l of radioactive material from this burial site. The Radiation 1 Control Branch of the Department for Human Resources of the l

'. Commonwealth of Kentucky has adequately evaluated the potential effects to the'public health and shfety through its environ-l mental monitoring program and is continuing this program in order to detect any problems that might arise in the future.

, Recommendations to be considered by the State concerning their environmental monitoring program are contained in Section IV of this report. Of special significance is the need for additional isotopic analyses of radiologice! samples. These are necessary to distinguish between the natural radioactive environment and that material which is being released from the site. By doing the above, the actual potential human exposure i i can be better estimated. Also, the anal ses can serve as bases for the measurement of radioactive material migration.

Notwithstanding the above, the data on tritium concentrations in the water sampled from Test Wells ,11 E (located onsite but in the unrestricted area) and 13 E (onsite and in the restricted area) are sufficiently high to merit consideration of further action. This is addressed in Recommendation No. A.5 l

III. Hydrological Assessment J

A. e Site Description and Operations

. The site is on a relatively flat hilltop in north centra'l Kentucky. Most precipitation (annual average of about 47 inches) that falls on the site runs off and into small streams.

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i Precipitation ~that does'not run off is either evaporated, consumed by vegetation or percolates into the ground. The 1 fraction that percolates flows at a low rate into. underground

. . zones for eventual drainage to seeps, wells and stream channels.

The subsurface material is composed of succe'ssive layers of different shales,and sandstone. The surficial layer is clay,

. a weathered shale. Groundwater is considered to move through ,

cracks and fissures in the shale.

Although the radioactivity detected in the offsite environ-ment prssenfs~no significant health problem to the population residing in the area, removal of water from th'e trenches is necessary to minimize the potential for the migration of

- e radioactivity. The licensee has performed a' considerable amount of work to reduce the infiltration of surface water into completed trenches in the older section of the burial

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facility. This work includes grading and improving surface i drainage, recapping of trenches with clay, and establishing a j vegetative ground cover over the capped trenches. Improved j methods are currently being used in the completion of newer i trenches to minimize the. infiltration of surface water into  ;

the trench'es. We believe these methods are necessary to i minimize the infiltration of water into completed trenches.

It is not possible to assess the co'plete m effectiveness of these efforts at the present time. l The State requires the licensee to remove water from open l l trenches and to remove liquids collecting in closed trenches.

1 The licensee has established.a program to pump water from the trenches until the trenches reach a dry status as defined in the license. The licensee has installed an evaporator system to treat and process liquids removed from the trenches. The liquids are first pumped to a temporary liquid storage area adjacent to the ol'd burial area and subsequently processed' through the evaporator. We believe these actions are appropriate in order to minimize the movement of contaminated water from the trenches to the underlying geologic formations.

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. The tempo'rary liquid waste storage area consists of steel tanks having a total capacity of about 600,000 gallons. The storage area is surrounded by a berm or dike approximately four feet high. At the present time about 500,000 gallons of ,

liquid waste is stored in this area. An apparent deliberate '

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act by a person or persons unknown last winter r,esulted in the cont.ents of one of these tanks being dumped within the berm area. Consequently, all rainfall which is collected within

- the area must now be treated as radioactive liquid waste. All

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l rainfall collected within the area is now being transferred to a newly lined pond. Leakage from the pond and dilution by additional rainfall is minimized by confining the contaminated liquid between two impermeable membranes. There are two additional onsite ponds: one is used as a non-potable water supply and the other is a surface drainage pond. The' licensee's l efforts to minimize the quantities of water stored on site

! , should be continued. It appears that the problem of migration of radioactivity at the site can best be controlled by further improving surface and groundwater management techniques at the site.

B. Conclusions After visiting the site and re'iewing v data collected by the Commonwealth of Kentucky, the Nuclear Engineering Company and various federal agencies, we conclude that to date the wastec are being entombed at the site and in an environment containing significant amounts of groundwater. The. continuous use of the groundwater evaporator has, in our opinion, substantially.

reduced the offsite migr,ation of contaminated water. Actions should be taken to improve the water management program, minimize the need for the evaporator, and further reduce

, offsite migration of low level radioactive water. Recommended measures to accomplish these objectives are set forth in Section IV of this report.

, IV. Recommendations The following recommendations address several methods which should be considered by the State to improve water management and site operations. Improved water management should minimize the potential for migration of radioactivity from the burial trenches. Each should be evaluated on a cost effective basis. The specific recommendations in A below relate to immediate improvements and' should be considered by the State 'for implementation in the near term. The general recommendations in B below address additional measures which could be considered if the water management aspects of site operations do not improve. These should also be cons.idered in lieu of or in conjunction with the proposed studies of the Environmental Study Design Committee, i.e., if conditions at the site do not improve and the monitoring programs indicate increasing levels of environmental radioactivity, further positive actions to improve the water management program should be taken as opposed to only studying the site.

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I A. Specific Recommendations for Consideration by the State

1. The height of vegetative ground cover should be kept to a l minimum. Long grass will hold the rainfall and give it a longe'r period of time to infiltrate, thus increasing the '

amount of' groundwater. l

2. The density of the top surface layers of soil should be l i determined. If it is not compacted to near optimum -

l levels (as determined by the standard American Association l

of State Highway Officials compaction methods), engineering methods should be used to obtain maximum compaction. If an optimum surficial density cannot be obtained, the surface c'ould be covered with a well compacted layer of 1 some essentially impervious material, such as clay or l soil cement.

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3. The method of measuring water extracted from the trenches, ,

l as defined in the license, should be evaluated. Water extraction measurements could be improved by requiring ,

the measurements to be volumetric rather than by pumping )

. rate. Consideration should also be given to pumping i trenches more frequently at a lower rate than presently-cpecified to minimize water accumulations, contact with j waste, and potential contamination of groundwater.

4. The effect of the onsite non-engineered ponds on the  !

groundwater table should be evaluated. These ponds i should be eliminated or lined unless it can be demonstrated l that they do not significantly enhance dissolution of  !

) radioactive materials in the trenches and increase the .

l rate of mov'ement of contaminated groundwater.  !

5. The program for measuring source terms (radioactivity being released in the evaporator eff,1uent and that present in trench water) and the environmental monitoring program

, being conducted by the licensee should be continued. The State should assess the licensee's program to be sure it includes nuclide analysis of evaporator effluent releases, trench water and appropriate environmental media (air, water, soil, crops and other direct pathways to man). An ,

air sampler should be placed at the nearest residence north of the site. The monitoring program should be such that it is possible to evaluate the environmental impact i from all significant pathways such as breathing, drinking water, eating fish, etc. It should provide information needed to determine whether public exposures are within j established limits and to ensure that long term buildup of

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i specific radionuclides in the environment will not become significant. The State may exercise its regulatory function to ensure quality assurance'and compliance by splitting samples, spot checks, etc., or by carrying out I an equivalent environmental cionitoring program.

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6. , With respect to the results of tritium analyses of water  !

t' samples taken from test well 11 E we believe the waste in Trench No. 31 containing about 650,000 curies of tritium ,1

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is the most likely source. An assessment should be made "l

of the feasibility of isolating this waste in place or j

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removing and disposing of it in an appropriate manner.

Such an assessment should be perfo'rmed on a cost-benefit l

basis including consideration of any additional radiation

. safety problems that may be created by such measures.

I With respect to the radioactivity data from test well 13 E, it appears that the most likely source is waste t

I buried in Trench No. 33 L. This trench should be brought to a dry state to determine if tritium levels in well 13 E can be reduced. ,

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B. General Recommendations 4.'or Consideration by the State -

1. Measures could be taken to intrease the ability,to remove l water frem future trenches (once they are close'd), )

Originally the trenches w.ere to have a gravel drain on i

, the bottom. This practice was later discontinued because the backfill material v.as apparently clogging the gravel. j Clegging could be prevented if an adequate layer of sand j was provided on top of the gravel. j

2. Lined channels could be provided between and around the capped trenches to speed the removal of runoff and thereby decrease the time available for rainfall to infiltrate into the soil.

3.- If the deep hydro-geological study proposed by the Environmental Study Design Committee is initia,ted, an att'empt should be  !

made to determine the extent of the' pervious zone indicated by EMCON Borings 2E, 7E, 8E, 10E, and 12E.- The. zone should be located and its leakage investigated. The' zone should be grouted with a suitable slurry material, such as clay, if it can be determined that the zone contributes significantly 3 to offsite groundwater flow.

, A similar technique could i be used to seal any otner leaky zones encountered as a .

result.cf subsurface explorations. ~

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4. The need for d e proposed mantle study woul'd be obviated by succe.ssful reductions in percolatica. Suusurface explorations co'21d also be used to establish whether , '

groundw'ater is reaching the site in the near surface '

I strata by flowing from the north and acetheast. If it was determined that a sigts.ficant amount of water is reaching the site in this manner, an intercepted ditch could be constructed a, cross the north end of the site. '

5. Consideratico could be giv'en ca ef fect:.vely encapsulating buried waste Li an impervioua aide and bottom trench 33ner.

Such a . liner could be constructed of bentonite, hydr aull:

asphalt or othe: durable impetvious material. Because cf the manner in which was e is disposed of, cuch a line.

. would have to be. constructed in sp:tions alens a tren 5.

C. Summary A number of proposals for investigating the Maxey Flats site have been mada. While studies for learning more about site conditions have nerit, we belle:e careful contider. tion of positive artrio::s 'to red 6ce offsite migration of c6ataminated water should be considered.

If conditions 4t tha. site do not improve cnd the monitoring programs indicate :.acraasing levels of environmental radia- '

activity sufficient te be of pu,blic health conce rn, con tingtocy actions should be instu.tuted. State and licensee 6fforts to develop a contingency plan should be continued in the event corrective action is deemed necessary based upon tF.a recults of the environmental m:nitoring program.

The State has requested that NRC contribu,te to the costs of the studies recommended by the Environmental Study Design Committee. The' review group considered this matter from a technical standpoint and believes that the information expected .

to be obtained from the recommended studies will be sufficiently site specific so as not to be of d*ract applicability to other

, NRC activities. Therefore, the review group does not recornend that NRC provide financial assistance 'tc the studies.

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APPENDIX A 1 x ,

ERC REVIEW GROUP MEMBERS I

G. Wayr.a Kerr, Chief (Chairman)

Agreements & Exports Branch l Division of Materials & Tuel Cycle.s Fa8111ty Licensing

, Office of Nuclear Material Safety and Safeguards

, William Gammill; Chief-l Site Analysis branch Divisior of Technical Review

, Office of Nuclear Reactor Regulation l

I Jacob Kastner, Chief l Radiological Assessment Branch Division of Technical Rcview Office of Nuclear Reacter Regulation i

L. G. Hulcan Site Analysis Branch G. P. Turi . -

Site Analysis Branch J. S. Bland l RadiolcyicalAssessmentBranch P. h. Lohaus Agreements and Exports Branch 4

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• 1 APPENDIX B Action Being Taken by the Commonwealth of Kentucky Regarding Implemen-tation of Recommendations as Set Forth in the Six Month Study Report.

• A. On January 7, 1975, the State informed the Nuclear Engineering Co. j (NECO), the site operator, of the results of the State's six-month study. Their letter stated that co,nclusions drawn from the study indicate the site is contributing radioactivity to the environment.

They requested NECO to notify them of the steps NECO is taking and future actions to.be taken to assure that the site does not contribute further significant radioactivity to the environment. The NECO response consisted of a report of their environmental study committee.

, The primary conclusions of the report are:

1. No long term increasing trends in environmental radioactivity are observable from NECO's environmental monitoring data.

2. The present extensive environmental monitoring program should be continued for two years after all trenches reach a dry status.

3. No physical remedial actions are planned until the monitoring program mentioned in No. 2 is completed. (NECO plans to decide on what physical remedial actions should be taken based on an analysis of data gathered through the monitoring program.)

NECO does not fully agree with the conclusions drawn from the State's study, particularly since they believe their data, covering l

a longer period of time than the six-month study, shows no trends ,

toward increasing levels of environmental radioactivity. However, the Company has agreed during discussions that the State data indicates the site is contributing small quantities of radioactivity to the offsite environment as any nuclear facility would. They believe the problem, lies in how the data is interpreted, and they believe neither the State's data nor their data show any real potential for human exposure to persons living in the area.

B. The State expanded their Radioactive Waste' Disposal Environmental Study Design Committee to include representatives from the l i

U. S. Geological Survey Kentucky Geological Survey J Nuclear Regulatory Commission Environmental Protection Agency Energy Research and Dev.elopment Administration ~

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Kentucky Science and Technology Commission Kenu , y Department for Natural Resources and Environmental ,

Protection Kentucky Department for Human Resources The Committer, met on February 18-20, 1975, and developed a six point program to be considered for further studies at the site as listed below by priority: s i 1. Deep Hydro-Geological Study l 2. Surface Run-Off Water

3. Mantle " Study (Weathered Zone)

4. Definition of Source Term

5. Agricultural Pathway l

6. Environmental Biologica1 Pathway

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1 The State is proceeding in the implamenta' tion of these studies and I has requested financial assistance from several federal agencies  !

including the NRC. Presently, the EPA is conducting the Agricultural Pathway study at no cost to the State. NECO, with some State participation, is conducting the Surface Run-Off Water study. The  !

Department of Human Resources staff has recommended that the Environ- l mental Biological Pathway study be initiated. The State plans to l

', take no action regarding the other studies until they receive a  !

response.to their Tequest for financial assistance from the federal  !

agencies.

, C. The State has continued to expand its comprehensive environmental monitoring program at the site. Prior to the six-month study the State was sampling 12 stations for water at a monthly frequency.

The program has been expanded to include 30 sampling stations which i are sampled on a bi-weekly basis. In addition, the State and NECO have established a split sampling program and certain samples are aisc analyzed by the EPA. The results of the split and tri-sampling programs are in substantial agreement. - l l .

D. The State is proceeding with amendment of NECO's license to require improved. site operating procedures, burial containment, and environ-mental monitoring by NECO. The license is presently being renewed and amsnded in its entirety. The primary changes proposed to be made in the license are:

1. Improved trench construction and completion including the placement of three sumps in each trench recessed into the 4

trench wall to prevent shear.

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2. Improved method for keeping water off the active face of I waste in the trench. )

3. The containment'of critium contaminated waste in ceramic j material when the specific activity exceeds 10 microcuries j per milliliter and buried such that the container will not j

be breeched. (

4. Restriction on the stack, effluent from the evaporator to reduce the contribution of radioactivity to the environment.

3. Continuation of water management program. The State has renegotiated the agreement between the State and NECO

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which provides that NECO will supply a security in the j amount of $430,000.00 tb assure that NECO carries out the i water management program as specified in NECO's " Plan of Corrective Action and Schedule of Compliance" previously filed with the State and incorporated into NECO's license.

The money will go to the State if, NECO fails to carry cut the program. The agreement was signed on March.19, 1975, has no expiration,date, and will not expire until n11 trenches' reach a dry status as defined by the license.

E. The State has requested and has obtained the opinions of two federal agencies relating to the appropriateness of applying a more restrictive criteria than the Maximum Permissible Concentrations (MPC's) as specified in the Kentucky Radiation Regulations to the potential

' migration of radioactivity from shallow land radioactive waste l disposal facilities. Both EPA.and NRC indicated that the philosophy i of total containment should be applied to the burial of radioactive {

! l waste and the design, objective of a site should be such that all )

waste is retained within the site boundaries throughout its hazardous i lifetime. The NRC stated that the MPC's and "as low as practicable" I concept are not appropriate for application to the migration of {'

radioactive waste from.a burial site except that the MPC va' lues are appropriate in assessing the public health significance of the radioactivity detected. '

F. The Kentucky Science and Technology Commi.qsion has appointed a task i group to study, evaluate, and determine the changes which may be needed in the perpetual care and long range maintenance program for the site and '_he associated financial responsibilities for carrying out the program, i

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APPENDIX C Action Being Taken by the Nuclear Engineering Company, Inc. (NECO,)_

Several actiona are listed below which NECO has taken to improve conditions at the site. Several of these were initiated prior to the six month study performed by the State. j A. l NECO appointed a three member internal task group to study the  ;

State's and the Company's environmental data. The Task Group j prepared a report which was submfteed to the State in response to j l

the State's 1/7/75 letter. (See Item A in Appendix B ) j i

B. NECO has conducted a surface run-off study. The report of thetr study is being prepared for transmittal to the State. They found i

several surface areas onsite which were contaminated and cleanup )

work on these areas was started in March 1975. "he State partic-1 pated in a part of this study and believes the drop in lev.els at certain sampling stations is attributable to the cleanup operations being undertaken by NECO. {

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C. NECO has :'ncreased their own environmental monitoring program to 4

I coincide with that being conducted by the State. They are partic-ipating in a split sampling program with the State and have obtained f j

better onsite laboratory instrumentation capability for sample analyses.

l D. NECO proposed to the State that future burials of tritium, which exceed a specific activity of 10 microcuries per milliliter, be I

contained in ceramic material. The State p)ans to incorporate this l condition into the license with the additional condition that the container be buried such that the container will not be breechcd.

E. NECO believes all phases of the operation have improved and cited the following examples: {

1. New management and site operations personnel have beca hired.

The operation of the site has received increased management I

attention. Quarterly meetings and unannounced inspections of the site and operations are conducted by management with site operations personnel, i i

l l 2. Improvement in the surface water management program through better control of surface water 'an-off, grading, rescaling (capping) of existing trenches and the establishment of a i

vegetation cover on these trenches.

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3. The conduct of an extensive water management program to remove water from the trenches. An evaporator system has been installed to reduce t;he radioactivity and concentrate the liquids pumped l from the trenches.

4. Increased attention to site operations and the mater 1als j received from customers for burial. A new form for use by j

customers in reporting the material being shipped for burial has been developed. ,

5. The conduct of hydro-geolcgical evaluations of the site and based -on thes.e evaluations development of a master site development plan and a revised radiation safety plan for site operations. These involve new methods for preparing and utilizing trenches, the installation of three sumps per trench recessed into the trench wall, improved capping procedures, and methods for keeping water off the open fsee of waste in the trench.

6. Twenty-four of the 42 completed trenches have been brought to a dry status as defined by the license.

7. Efforts are being made to reduce: 1) the quantity of water

• stored at the tank farm which subsequently is processed through the evaporator; *nd 2) the size of the tank farm.

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