ML20234D227
| ML20234D227 | |
| Person / Time | |
|---|---|
| Issue date: | 12/11/1987 |
| From: | Hawkins E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | Snell W TEXAS, STATE OF |
| References | |
| REF-WM-43 NUDOCS 8801060507 | |
| Download: ML20234D227 (2) | |
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DBangart, RIV 1-GKonwinski DLacker,.RCPD, TX LLO Branch,'LLWM
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DEC I i 1987 i
URF0:GRK Docket No. WM-43
.040WM043150E Texas Department of Health ATTN: Warren D. Snell, Chief Bureau of Radiation Control Uranium and Nuclear Waste Management Program 1100 West 99th Street Austin, Texas 78756-3189 L
Gentlemen:
Our office is in receipt of your November 18, 1987 correspondence transmitting the conceptual closure plan for the Panna Maria facility operated by Chevron Resources Company.
As you.have indicated in your cover letter, this is a conceptual plan.
Due to-this, our comments will be general in nature and directed to specific sections of the-plan.
The licensee states that the tailings area reclamation "will begin by systematic draining and/or evaporation of ponded liquids." It is assumed that the referenced draining will be water movement within the tailings.
impoundment to facilitate evaporation rather than discharge.
The staff l
is not aware of a treatment method that would be acceptable for'any type-of discharge of tailings solutions.
Additionally, the licensee may want i
to consider some type of enhanced eva This would not only speed up the dewatering process,poration system.
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but also, serve as a form of i
interim tailings stabilization.
The surface cap that is discussed by-the licensee is one of the major-components of the. reclamation plan.
As you are aware, it will be necessary for the licensee to develop construction techniques.and performance standards for the cap placement.. Similarly, an appropriate and verifiable emanating fraction, average tailings radium content and l
soil properties will be necessary to support utilization of the RADON l
computer code.
i 0FC :
NAME :
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DATE :87/12/11 8801060507 871213
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..__J.;;:33 WM-43/GRK/87/12/10/0 DEC 11 1987 2-The drainage plan as discussed, raises several issues which need to be l
resolved.
A single " drainage outlet" is referenced as a " Berm around the perimeter of the cap."
It is difficult to. predict the longevity of these types of earthen structures.
However, of greater concern is the design assumption that they will be sized to a 200 year, 24-hour, rainfall event.
It is the policy of the NRC to require a hydrologic design that utilizes the probable maximum precipitation.(PMP) event.
As a design guide, it is generally assumed that flows generated by the PMP must be limited to a velocity of 3 feet /second.
Exceeding this velocity may result in erosive velocities that will require the use of durable riprap.
Similarly, the 3:1 slopes discussed by the licensee would not be considered stable for 200 to 1000 years.
It is our practice to utilize i
much less steep slopes, generally in the'10:1 range or less.
l The proposed vegetative cover is a matter in which our office lacks expertise.
However, we have every confidence in the recommendations of the Karnes-Goliad Conservation District recommendations.
The processing area and ore pad are proposed to be' cleaned and then revegetated.
The cleaning process must ensure that the requirements of 10 CFR Part 40, Appendix A, Criterion 6, are accomplished.
As verification of the licensee's decontamination work, it is our policy to request a gamma survey accompanied with representative soil samples analyzed for radium-226.
In this section, we also defer to more competent individuals when considering revegetation.
If you would care to discuss these comments in further detail, please contact Gary Konwinski of my staff at (303) 236-2819.
Sincerely,
/5/
Edward F. Hawkins, Chief Licensing Branch 1 Uranium Recovery Field Office Region IV Case Closed:
040WM043150E 0FC : U URF NAME : onw ki/lv EHawkins DATE :87/12/11
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