tIMEMORANDUM TO:

FkOM: '

SUBJECT:

A_>) February 21, 1997

Hubert T. Bell, Inspector General

Office of the Inspector General

Michael J. Bell, Chief

Engineering and Geosciences Branch

Division of Waste Management

Office of Nuclear Material Safety

and Safeguards

/S/

MEMORANDUM OF UNDERSTANDING AND INTERAGENCY AGREEMENT BETWEEN

THE U.S. DEPARTMENT OF ENERGY AND THE U.S. NUCLEAR REGULATORY

COMMISSION ON THE CLOSURE OF HIGH-LEVEL WASTE STORAGE TANKS AT

THE SAVANNAH RIVER SITE

By letter dated December 20, 1996 (Attachment 1) from L. Watkins, Assistant

Manager for High-Level Waste (HLW) at the U.S. Department of Energy (DOE)

Savannah River Operations Office, to C. Paperiello, Director, Office of

Nuclear Material Safety and Safeguards, DOE requested technical assistance

from the staff to evaluate DOE's general methodology for the "incidental"

waste classification of the residual material in 51 HLW storage tanks, after

they have been emptied of their contents. DOE plans to close the empty tanks,

and residual tank wastes classified as "incidental' would not be subject to

NRC licensing authority.

DOE also recognized in its letter that a funding arrangement would be

necessary to support NRC involvement in its tank closure activities. In this

regard, by letter dated February 7, 1997 (Attachment 2) from L. Watkins to C.

Paperiello, DOE submitted a proposed funding mechanism in the form of a

Memorandum of Understanding (MOU) and Interagency Agreement (IA) for the

staff's consideration. The proposed MOU/IA are attached (see Attachment 2)

for your review.

Please provide any comments on the MOU/IA directly to R. Weller of my staff.

Attachments: As stated

CONTACT: Richard A. Weller, NMSS/DWM

415-7287

9703060018 970221

0t9SS7SUBJ CF

DISTRIBUTION: (w/atts)

£tfMIVFlFei NMSS r/f ENGB r/f

JGreeves MFederline BJDavis

NRGi PLU CSER COPY

DOCUMFNT NAMFE SA\DWMFNIMJRAII\SR-MOUIA.-M

IOFC.| ENGB,?A Xa Ir | END$B - I ll

NAME RWeller/eb/Pf¢ I MBI-- ,

DATE 21/97 lL 2/JZI97 | I

OFFICIAL RECORD COPY

,, 14-xr

pA7,*

ACNW:

N.A. IG :

LSS:

YES

YES -

YES

NO -

NO - NO -7

050069

Delete file after distribution:

pJS: W0

Yes ___ No
A

ATTACHMENT I
DepEatment of Energy

Savannah Rivv' Operations Office

P.O. Box A

Aiken, South Carolina 29802

DEC 2 0 1996

Dr. Carl J. Paperiello

Director

Office of Nuclear Materials and Safeguards

United States Nuclear Regulatory Commission

Washington, D.C. 20555-0001

Dear Dr. Paperiello:

SUBJECT: Savannah River Site (SRS) High Level Waste (HLW) Tank Closure; Classification

of Residual Waste as Incidental

I appreciated the opportunity to meet with you and your staff this past September 17, 1996, to

discuss the U.S. Department of Energy (DOE) Savannah River Operations Office (SR) plans for

closure of the 51 HLW storage tanks on SRS and the classification of the residual waste as

"incidental".

SR has determined that all 51 tanks can be closed under existing Nuclear Regulatory Commission

(NRC) criteria for "incidental" waste as specified in the Bernero (NRC) to Lytle (DOE) letter of

March 1993; some will require use of concentration averaging and others will require additional

cleaning and the likely use of concentration averaging. DOE will assure that the waste: (1) has

been processed (or will be further processed) to remove key radionuclides to the maximum extent

that is technically and economically practical; (2) will be incorporated in a solid physical form at a

concentration that does not exceed the applicable concentration limits for Class C low-level waste

as set out in 10 CFR Part 61; and (3) will be managed pursuant to the Atomic Energy Act, so that

safety requirements comparable to the performance objectives set out in 10 CFR Part 61 are

satisfied to assure safety to the public. In order to meet all the above criteria we plan to proceed

forward with two separate approaches as follows:

* The first approach would close 14 tanks that meet the criteria stated in the Bermero to Lytle

letter. However, for most if not all of the 14 tanks, guidelines found in the NRC Branch

Technical Position (BTP) of January 17, 1995, "Issuance of Final BTP on Concentration

Averaging and Encapsulation, Revision in Part to Waste Classification Technical Position"

have been used to support meeting the Class C limits. Assuming the NRC takes "no

objection" to this methodology, these tanks will not require additional cleaning. These 14

tanks will be addressed as Category I tanks.

* The second approach would address the 37, Category 11, tanks that will require additional

cleaning, which could include an oxahc acid wash, and the likely use of concentration

averaging to meet the above criteria. The cost for the additional cleaning is approximately $800,000 per tank.

Concurrently with Category I tank closure activities, SR is requesting the NRC to review the SR

general methodology and application of the Bernero to Lytle letter, particularly Criteria 2 to high

level waste tank closure. With regards to Criteria 2, SR specifically requests under 10 CER

61.58, consideration of an alternative to the Class C limits of 10 CFR 61.55 for tank closure as

the intruder scenarios for Class C determination may not be appropriate; the residual waste will be

qF~t q1 7
Dr. Carl J. Paperiello 2 DEC 2 0 V6

immobilized and the tank will be filled with a stable medium, and thiltrt-ormance objectives of 10

CFR Part 61 will be met. These points are discussed further nE 1Te below paragraphs. SR

recognizes that consideration of 10 CFR 61.58 for Criteria 2 may .also require NRC evaluation of

SR application of Criteria I and 3 SR recognizes that this will :eyplire further discussion and

evaluation by the NRC which SR will fund.

SR understands that Criteria 2 is based on protection of individuals from inadvertent intrusion.

However, with regards to SRS high level waste tank c!osure, access to and ultimate contact with

the waste from inadvertent intrusion is highly unlikely. The small amount of residual waste on the

bottom of the tanks will be located under approximately 40 feet of cement. Additionally, as

documented in the SRS Future Use Project Report qf January 1996, DOE intends to maintain

control of the site in-perpetuity. Therefore, the possibility of inadvertent intrusion into the closed

high level waste tanks and the areas surrounding the tanks will be remote. Consequently, the

intruder exposure scenarios used to establish Class C limits of 10 CFR 61.55 may not be

appropriate for tank closure. Re-evaluation and reconsideration of the appropriateness of the

Class C limits for tank closure would result in substantial cost savings as additional cleaning of 37

tanks may not be required. This approach will not affect meeting the performance objectives of

10 CFR Part 61 and human health and the environment will still be protected.

10 CFR 61.58, states that the Commission, on request, may authorize other provisions for the

classification and characteristics of waste on a specific basis if, after evaluation of the specific characteristics of the waste, disposal site and method of disposal, it finds reasonable assurance of

compliance with the performance objectives in Subpart C of 10 CFR Part 61. Section 3.9 of the

above referenced BTP further states that alternatives to the determination of radionuclide

concentrations for waste classification purposes, other than those defined in the BTP, may be

considered acceptable. Additionally, the referenced BTP states that the physical form of certain

discrete wastes may be such that intruder exposure scenarios, other than those used to establish

the values in Tables 1 and 2 of 10 CFR 61.55, may be appropriate. The referenced BTP

specifically mentions the disposal of a large inLact activated component filled with a structurally stable medium (e.g., cement). Subsequent to removal of waste from a tank, reducing grout will

be placed in the tank to bind up and immobilize any residual waste. The grout is formulated to

bind up the residual waste. The height of the reducing grout is dependent on the amount anid

characteristics of the residual waste. A low-strength cement, Controlled Low-Strength Material

(CLSM), forms the next layer (approximately 7500 cubic yards) on top of the reducing grout. The final layer consists of a high-strength cemrent at the top of the tank (approximately 1500 cubic

yards of cement, 5 feet high). The attached figure provides a typical tank closure configuration.

The first four tanks that will be closed at SRS in order are Tanks 20, 17, 19 and 18. The following provides the amount of reducing grout required in the first four tanks to meet Class C limits using concentration averaging based on the guidelines of the aforementioned NRC BTP: Tank 20 - 2.2

inches; Tank 17 - 12.5 inches; Tank 19 - 2.2 inches; and Tank 18 - 13.2 inches. Qualitative tests

conducted by Construction Technology Laboratories (CTL), Inc. indicate that mixing occurs

between the residual waste and the reducing grout. Based on the preliminary qualitative CTL test

results, for SRS to proceed forward with closure activities for those tanks would involve only minimal risks. A copy of the CTL report, "Development of Reducing Grout for Closure of

Savannah River Site Tank 20" of October 1996, has been provided to the NRC staff At SR

request, CTL is conducting additional quantitative tests to verify the performance of the reducing

grout. Results from these quantitative CTL tests will also be provided to the NRC. This

information can be used to support evaluation of SR tank closure methodology. With quantitative CTL test results, SR will proceed with closure activities for Tanks 20 and 17 concurrently with

the NRC review of our methodology and the application of the Bernero to Lytle letter. SR plans

to commence closure activities for Tank 20 in early February 1997.
Dr. Carl J. Paperiello 3DC2019 3' DEC 2 0 1M

We recognize that an Interagency Agreement (IA) is necessary It; support the NRC involvement

in our tank closure activities. I will ensure that SR actions required to finalize the IA on an

expedited basis are performed.

As we discussed in a telephone conference call with your staff on December 16, 1996, NRC plans

to visit SRS to evaluate our tank closure activities in January 1997. 1 fully support this effort and

will provide anv assistance your staff may require for this visit.

I am prepared to further brief you and your staff on our plans for tank closure at your

convenience. Please contact me or Larry Ling of my staff at (803) 208-8248 if you have any

questions or would like to schedule a briefing.

Sincerely,

A. Lee Watkins

Assistant Manager for

High Level Waste

Ps-97-00 i

Enclosure

Tank Closure Diagram

cc:

S. Cowan, EM-30, HQ

R. Erickson, EM-32, HQ
SPWINELWI

~~~r 1

(

160oyd

3

asI5 ,7600d'

(

S o y d

TYPICAL TAJ 

K
ATTACHMENT 2