ML19317H517
| ML19317H517 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 06/05/1980 |
| From: | Hovey G METROPOLITAN EDISON CO. |
| To: | Jay Collins Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19317H518 | List: |
| References | |
| TLL-241, NUDOCS 8006120374 | |
| Download: ML19317H517 (13) | |
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Metropolitan Edison Company g-]
Post Office Box 480 Middletown. Pennsylvan,a 17057 i
717 944-4041 Writer's Direct oial Nurnber June 5, 1980 TLL 241 TMI Program Office Atta:
J. T. Collins, Deputy Program Director U. S. Nuclear Regulatory Commission c/o Three Mile Island Nuclear Station Middletown, Pa.
17057
Dear Sir:
Three Mile Island Nuclear Station, Unit II (TMI-2)
Operating License No. DPR-73 Docket No. 50-320 EPICOR II Resin Solidification The attached material is supplied in respcu.: to Item 5 of our letter of December 21, 1980 (GQL 1509), " Proposed Method for Solidification from EPICOR II."
The February goal for submittal of this advisory information was missed because of technical difficulties we have encountered in attempting to carry out the October 16, 1979 NRC Order to solidify EPICOR II resins. Those difficulties were referred to in the March 4,1980 letter to the Chairman of the NRC from the President of GPU, and were discussed in detail in our 4/11/80 meeting with NRC representatives. Attachment i summarizes our progress to date. is a description of the scope of work with Hittman Nuclear and Development Corporation which represents the main effort for EPICOR II Solidification at this time. Attachment 3 is a description of the test program to qualify cement as a binder for this application.
The intent of this letter is to provide status information to you.
In the near future, we expect to provide for NRC approval, our proposed course of action regarding EPICOR II solidification.
Sincerely,
/s/ G. K. Hovey G. K. Hovey Director, TMI-II GKH:EDF: hah DO!
Attachments S
cc: g THIS DOCUMENT CONTNNS P00R QUAUTY PAGES
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Metr ht n Edrson Company is a Memoer of the General Pubhc Utat:es System
' 800612037,
o Atttchment 1 TLL 241 EPICOR II SOLIDIFICATION PROGRESS 1.
Summary of Approach The Commission's orderl which approved operation of the EPICOR 11 system, imposed a requirement to expeditiously construct a facility for solidification of the spent resins prior to shipment. This attachment describes current status and ongoing efforts in this regard.
Io date it is not apparent that 2PICOR II resin solidification will be a simple extension of existing state-of-the-art technology. From studies to date of possible nethods to solidify EPICOR II resins, it is elect that:
The process and systems for solidifying demineralizer e
resins cannot be considered to be a widely established practice in the U. S. commercial nuclear industry. There is sone experience but most plants are shipping resin in the dewatered state as is allowable through June '81.
The sluicing of resins in the quantities and activities e
anticipated in order to solidify EPICOR II resins is un-precedented. About three thousand cubic feet of resins from one hundred or more liners, some of which will have material of the order of one curie per liter (30 curie per cubic ft) will have to be sluiced. Assuming that on the average one liner can be sluiced every two days leads to 1On October 16, 1979, the Director, Office of Nuclear Reactor Regulation issued an order for modification of the TMI-II license. As part of this order under subpart (iv) it was ordered that:
"The licensee shall not ship resins offsite unless they have been solidified and only then with the prior approval of the Director of NRR, pr'ovided however, that the licensee may ship non-solidified but dewatered spent resins offsite if it determines, and the Director of NRR concurs that such shipment is required to assure continued operation of EPICOR II or otherwise required to protect public health and safety. The licensee shall expeditiously construct a facility for solidification of the spent resins and shall use such facilities for resin solidification upon receiving the Director of NRR's concurrence with the design and operating procedures." -
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o etnclu31on that cicco ts a yaar will b3 rsquirzd ef tsr systems are in place to complete the sluicing and solidifying of EPICOR II resins.
An acceptable binder far solidification of EPICOR II resins e
has not been suitably determined. That is, there is a lack of clear criteria 2 from NRC as to the performance requirements of a binder, there is not a sufficient data base to be able to demonstrate that binders will meet performance requirements without specific application testing, and the effect of demineralizer media variations and contaminants is unknown.
Industry experience in recent years with some of the unsuccessful attempts to solidify with urea formaldahyde which resulted in the formation of a corrosive liquid emphasized the importance of approaching the soliditication of EPICOR II resins with great care.
Based on our review of the various binders potentially e
available, it appearc that cement is the only binder for which there is a resionable chance that a solidification system could be designed and installed in a period of less than about two years.
For these reasons, a careful approach is being taken to the solidification of EPICOR II resins. The approach can be viewed in two aspects. One is demonstrating the acceptability of cement as a binder / matrix material for the EPICOR II resins.
In this regard, the qualification will be based on achieving a free-standing monolith that will retain its configuration upon immersion in water for a few days.
It is important to note that our
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qualification program does not address leachability or require uniform distribution of resin in the binder.
The reason for not addressing leaching is that no criteria have been established. As requested by NRC representatives in a meeting with i
Metropolitan Edison on April 11, arrangements are being made to furnish a
s 2For example, the January 29, 1980 NRC letter from D. Eisenhut to all licensees requiring solidification after June 1981 does not contain leaching criteria; however, representatives of NMSS have indicated that the final version of 10CFR61 will have leaching requirements (which the current draf t does not have).
BNL with samples for the purpose of their conducting leachability tests.
In this regard, we note the judgement expressed by Dr. Schweitzer of BNL at the meeting that the leachability of organic resin in cement may be no better than the leachability of organic resins without a binder. This judgement is further demonstrated in a BNL report.
Demonstration of the mixing of resins and binders will be limited to demonstrating tha absence of unsolidified material and voids. We anticipate that it may be difficult to achieve a uniform distribution of the resin and do not perceive a particular advantage to doing so.
The second aspect of the approach is selecting a solidification system. The most significant complication regarding system selection is how to transfer the highly radioactive EPICOR resin into a vessel where it can be mixed with a binder. This generally involves a system to sluice the resin into either a liner with an internal mixing device or into a drum that can be rotated. Because of the problems inherent in sluicing those resins, j
our effort at this time is concentrated on modifying liners for use in the EPICOR II system which can be solidified with cement without sluicing.
2.
Binder (Solidification Matrix) Selection Cement Cement is considered the lead candidate for a binder because cement solidification sys ~ us are operational on a commercial basis which supports the NRC order to p..,ceed expeditiously.
We are proceeding to demonstrate the acceptability of cement as a solidification medium for EPICOR II resins. This is not considered to be a trivial goal, witness the failures to maintain a defined solidified package that have been demonstrated by HEDL.4,5 Based on conversations with national laboratory s
Status Report on Leachability, Structural Integrity, and Radiation Stability of Organic Ion Exchange Resins Solidified in Cement and Cement with Additives, May 1980, R. E. Barletta, et al, BNL.
HEDL-TME-77-40, Division of Waste Management Production and Reprocessing Programs Progress Report for January-December 1976.
SHEDL-TME-77-74, Division of Waste Management Productions and Reprocessing Programs Report for January-June 1977.
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.,.3 researchers and with vendors, it is clear that there is limited experience and a dearth of knowledge regarding the specific failure mechanisms. On the other hand the chemistry of cement is fairly well understood and is non-proprietary thus avoiding
- management problems and potential information voids associated with proprietary products. Consider.ng the problems associated with resins as highly radioactive as those from EPICOR II, it is paramount that binder characteristics be well understood.
In order to establish the acceptability of cement, Hittman Nuclear and Development Corporation (HNDC) has been contracted, with Mr. Levendusky of EPICOR &s a subcontractor, to conduct tests for this purpose.
(Attachment 3 herein.) The selection of RNDC takes advantage of the availability of their mixer design to be applied to the EPICOR II liners (discussed later). The purpose of the tests is to establish the range of parameters (for example, water, cement, and resin fractions) which will result in a monolithic structure.
Screening samples will initially be qualitatively evaluated followed by small scale primary tests to qualify the acceptable mixes. This will be followed by drum sized and then full sized liner demonstration. NRC and its consultant, Brookhaven National Laboratory, will be observing the testing.
Urea Formaldehyde (UF)
Based on past problems with UF, i.e.,
problems with its release of water, and its potential for forming corrosive compounds, it has not been considered.
In general, industry practice is to move away from UF solidificatien.
Bitumen (Asphalt)
Bitumen has been deferred from near-term consideration because of the long lead time to deliver a system and the complex nature of a facility to support it.
Also of concern is its combustible nature.
l DOW Binder Dow binder is currently in the developmental stage for application to resin solidification (as well as other wastes) by several equipment swadors (e.g. Stock, Hittman, Chem-Nuclear, Epicor). However, we do not consider the application to be commercially demonstrated to the stage l-
i that would allow us to proceed " expeditiously". As we understand, current processes require the material to be solidified to be added to a pre-loaded
-batch of binder which is being stirred. This could present difficulties in system design because of the need to sluice resins with excessive volumes of water.
We note that TMI-I is considering a Dow binder system for in-plant In the Unit I case, rel'tively small volumes of resins application.
a will be mixed with evaporator bottoms to sluice into the binder. The primary waste to be solidified in this case is evaporator bottoms and thus there is no analogy to the EPICOR II case because there is no excess sluicing fluid.
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Delaware Custom Material Discussions have been held with..laware Custou Equipment Company (DCEC).
In their process, portland cement is mixed with an aqueous silicate solution and pulverized shale. It is not anticipated that solidification process by this method would differ substantially from that of a standard cement system.
If judged desirable to develop a cement-based alternative, the process will be evaluated for its potential to provide additional flexibility for solidification operations.
Vitrificiation Potential offgas problems, unknown waste preconditioning requirements and system complexities imply that a comprehensive R&D project would be required before vitrification could be considered for near-term utilization.
Since such a program is contrary to the order to proceed expeditiously, vitrificiation has been ruled out from further consideration. GPU, however, 4
has suggested to DOE that a vitrification system, as well as others, might be considered for demonstration at TMI-II.
t Epoxy Epoxy systems have not been investignted for this application, however, associated concerns are similar td those of the DOW binder.
3.
System Design Considerations The EPICOR II liners currently in use are not amenable to solidification i, -
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without transferring the resin to another container in which mixing operations can be performed. This requires sluicing of resins with water at a velocity sufficient to suspend the resin beads. To accomplish this, a comprehensive system including pumps, well contoured piping, tanks, liners, shielding, instrumentation and semi-remote handling is needed.
Additional occupational dose will result from the operation and maintenance of such a system.
To minimize sluicing operations, we are proceeding to design a modification to the EPICOR II liners which will allow in-liner solidification.
A most important aspect of this modification is that demineralizer efficiency must not be affected byunmodifiedinternal mixer, i.e', by flow channeling or flow bypass. Once this concern is satisfied, modified liners can be placed in operation. The use of modified liners will nevertheless result in an inventory of modified liners that still must be sluiced in order to be solidified. The number in this category will depend on the timing of the demonstration of a modified liner design. These liners will remain in storage until their disposition is decided upon.
4.
Efforts To Date Several specific tasks have been conducted regarding solidification which are described below.
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Ex-Liner Conceptualization Study A concept has been developed for a separate facility which would include systems to sluice resins from EPICOR II liners into solidification liners and associated solidification equipment.
The purpose is to provide a preliminary estimate of the cost, scope and schedule associated with such a facility.
A comparison of proposed solidification systems from two vendors were reviewed and a facility was designed around the most favorable which utilizes large liners with internal mixing devices. The work includes an arrangement, equipment list, description of sluicing adapters, P & ID and a description of the operation to solidify. As a result of this work, a decision has been implemented to commence use of modified cover 6 for the EPICOR II liners that incorporate a 4" diameter bung which would be useful for sluicing adaption. __
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The separate sluicing facility described in the study is estimated to take a year or more to design, construct and place in operation and would cost four to six million dollars.
Evaporator / Solidification Facility Separation An evaluation has been conducted for separating the solidification portion of the planned evaporat'or building for the purpose of allowing early completion of the solidification system.
The results show this concept has technical problems related to pumping of evaporator concentrates and also significantly impacts facility cost.
Consideration has been shelved.
In-Liner Conceptualization Study Concept development was conducted for a separate facility with the l
function of in-liner solidification.
In order to use such a system, a new style liner is required which has a built-in mixing device.
The liner modifications are described as is modification to the vendor's standard cement fill head. The operational steps in order to solidify are described. The results of this study show a facility
'chedule of about nine months and a cost of $700,000.
Ctatract Work A scope of work and purchase order has been placed, and work is under-way for the development and demonstration of an in-liner mixing concept and the qualification of cement as a binder for EPICOR II resins.
(See Attachment 2 herein.)
A comprehensive test program will be conducted to define the parametric limits of water, cement and resin that will result in a successful solidification.
In addition, full-sized liner tests are planned to ensure the liner modification will not degrade demineralizer performance.
A time-motion study is also planned for full-sized liners to support ALARA management. A few full sized liners will be solidified as part of the demonstration.
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Sluicing L/ stem / Evaporator Facility The ability to fit a sluicing system in the evaporator facility storage room will be assessed.
Dose Assessment An estimate has been performed of the person-rem exposure associated with EPICOR II solidification operations. The estimate is 75 to 90 person-rem without considering the unknown dose associated with unpredictable activities such as system upsets.
Strong Container Option The January 29 NRC letter to all licensees mentioned a " strong container" alternative to solidification. We are currently exploring the potential for such an approach.
5.
Near-Term Plans Assuming a successful demonstration of the modified EPICOR II liners which incorporate the mixing assembly, the modified liner design is expected to be used. The rationale for ordering this modification is to reduce,the amount of resin that must be sluiced. The actual solidification of resin in these liners will be addressed in terms of facility scheduling. Other near-term efforts include completion of the studies previously described.
As a result of these studies, decisions will be made on the combination of facilities and schedule for long-term planning.
6.
Long-Term Plans The actual solidification of EPICOR II resins may not start for a year or more because of the lead time needed to erect separate facilities or the potential desire to incorporate the mixing and/or sluicing capability for EPICOR II resin in the evaporator building. Thus, EPICOR II liners, both modified and those of current design, will be stored in the interim waste storage facility until such time as they can be removed for solidification and/or shipment. ~.
Atttchment 2 TLL 241 SCOPE OF WORK EPICOR 11 Resin Solidification Services 4
Metropolitan Edison Company Three Mile Island, Unit No. 2 HNDC Proposal No. E-819, Rev. 1 Phase I
'A.
Write Chemistry Test Program
' Write program for chemistry testing. The purpose of this program will be to ensure that the EPICOR II resins can be effectively solidified using cement.
Concurrent with the preparation of the test prvbram, resins will i
be procured from EPICOR for use in the tests.
Preliminary screening tests will be conducted to establish the mixing ratios to be considered based on set times, physical characteristics, packaging efficiencies, etc. Tests of the resin samples will be conducted on unexpended, partially expended, and expended resins with various pH adjustments. The tests will use both laboratory samples of approximately 500 mililiters, and drum samples (30 or 55 gallon). For purposes of estimating, approximately 50 small laboratory samples and 20 drum samples will be test solidified and sectioned.
In order to define the parameters and goals of the chemistry test program, HNDC will consult with General Public Utilities (GPU) personnel, Mr. Levendusky of EPICOR, Inc., and other cognizant persons as approved by GPU. HNDC will then prepare a written description of the test program based on the discussions held and will submit the program to GPU for approval prior to conducting any tests.
8.
Conduct Chemistry Testing Conduct the approved test program defined above.
For planning purposes, the test program will consist of release tests using trace chemicals, preparation of the laboratory and drum samples noted above, immersion tests, and pilot tests to evaluate the solidifica-tion process. The test results will 'be documented in a fonnat which has been pre-approved by GPU. The quality of the test results document will be suitable for submission to the NRC in support of GPU's proposal for solidification.
HNDC will give GPU one week's notice prior to conducting tests in order for GPU to arrange to have a representative present.
Rev. 1 03/18/80 l
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C.
Develop Solidification Concept, Design Requirements, and Design
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Criteria Concurrent with A and B above, an overall conceptual description of the solidification process and system, including design require-ments and design criteria for the so.lidification system and liners, will be developed. This document will be written to conform to GPU's format for submittal to the NRC.
Included in this effort will be HNDC's input to, and support of, others in the development of design criteria for a solidification facility.
Phase II A.
Design Solidification Liners and Equipment Perform detailed design of solidification liners, and of equipment necessary to perfonn demonstration solidification testing of those i
liners in HNDC's facility (for example, a modified mixer drive assembly to interface with the modified liner).
Designs will be reviewed and approved by GPU prior to commencing fabrication. HNDC personnel will also provide support to others in arriving at a conceptual design for the solidification facility.
B.
Fabricate Liners and Equipment Fabricate the liners (three 4x4 and one 6x6) and solidification equipment designed in A above.
C.
Write Test programs for Phase III Tests A test program document and test results outline for each of the Phase III tests discussed below will, be prepared and submitted to GPU for review and approval prior to conducting the tests.
Phase III A.
Conduct Flow and Pressure Drop Tests of Modified Liners Flow and pressure drop tests will be conducted using modified solidification liners. The purpose of these tests will be to verify that bypassing and short-circuiting is not occurring in the modified liners.
For purposes of estimating, one modified 4x4 liner and one i
modified 6x6 liner, each filled with resins of the type used in the EPICOR 11 system, will be tested.
Each unit will be operated using non-radioactive water to which chemicals will have been injected to simulate the ionic depletion of the resin. These tests will be conducted at the HNDC facility in Columbia, Maryland.
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_3 Trace amounts of non-radioactive Cesium and Strontium will be added and removal effectiveness will be determined using an HNDC atomic absorption unit equipped with graphite furnace.
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vill als_o be collected as the pressure drops through the undewrains as a function of flow rate. Upon completion of the initial tests, the chemical concentrations will be increased and the unit will be operated until a conductivity break occurs.
This data will be used to detennine whether unit life will be acceptable.
B.
Simulate Solidification Operations At the HNDC facility, solidification of a modified 4x4 liner will be simulated in order to acquire data for estimating personnel radiation exposures to be expected during actual solidification operations.
The simulation will include operation of thc mixing drive, but will not include the actual addition of cement or solidification of the liner contents. The area surrounding the liner will be marked to 3
indicate the various radiation zones anticipated for a hot liner
'within its process shield. HNDC personnel, with stopwatches, will monitor and record the time required to perform the various operations, and the time that personnel must remain in the various radiation zones.
Individual operations will be repeated to obtain an accurate assessment of the time required, and to determine the improvement that can be made as personnel improve their proficiency.
The results of this simulation will be utilized to optimize sol.idification procedures and equipment in order to at.nieve ALARA goals.
C.
Conduct Solidification of Modified Liners HNDC will conduct full-scale solidifications of modified liners e
containing representa'ive resins. For purposes of estimating, three 4x4 line'rs and one 6;. 1.iner will be solidified (to include the 6x6 liner, and one of the 4x4 liners, previously utilized in the flow and pressure drop tests). These tes'ts will also be conducted at HNOC's facility.
The containers with solidified resins will be sectioned to determine the adequacy of the structural members and the homogenity of the solidified product.
The results of all the Phase III testing discussed above will be documented in a fonnat which has been pre-approved by GPU.
D.
Prepare Process Control Plan and Operating Procedures The-Phase I and Phase III tests results will be utilized to prepare a Process Control Plan and detailed solidification operating procedures.
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Phase IV HNDC will prepare a brief planning document which will define costs, schedules, material quantities, etc., for conducting solidification of EPICOR 11 liners and transporting these liners to the burial facility in Richland, Washington.
DELIVERABLE ITEMS Phase I Task A - Chemistry Test Program Description Task B - Report on Chemistry Test Program Results Task C - Design Requirements and Criteria Document Phase II i
Task A - Detailed Design Documents for Modified 4x4 Liners Detailed Design Documents for Modified 6x6 Liners Detailed Design Documents for Modified Solidification Equipment
' Task C - Test Program Document and Test Results Outline. for Phase III Tests:
Flow and Pressure Drop Test Simulated Solidification Test Liner Solidification Tests Phase III Ta,sk A - Test leport on Flow and Pressure Drop Test Task B - Test Report on Simulated Solidification Test Task C - Test Report on Liner Solidification Tests Task D - Process Control Plan Operating Procedures Phase IV
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Planning Document Report l