Department of Energy Carlsbad Field Offlce P. O. Box 3090 Carisbad, New Mexico 88221 July 25, 2007

Mr. Ron Curry, Secretary New Mexico Environment Department 1190 St. Francis Dr., Suite N4050 Santa Fe, New Mexico 87502

Subject: Permittees' Assessment of the Potential Impacts to Human Health and the

Environment from Leaving the SWB Containing Drum BN10161094 Emplaced in the WIPP

Dear Secretary Curry:

As committed in our letter on July 20, 2007, this letter presents the permittees' assessment of the potential impacts to human health and the environment from leaving the standard waste box (SWB) oontaining drum BN10161094 emplaced in the Waste Isolation Pilot Plant (WIPP). This letter also describes the WIPP waste emplacement activities that the permittees have implemented to provide your office time to review this submittal.



### Assessment of Potential Impacts to Human Health and the Environment

The permittees have reviewed information known about the contents of this drum and have concluded that leaving the emplaced container in the WIPP repository is protective of human health and the environment. Enclosure 1 to this letter provides a detailed explanation of the contents of drum BN10161094 (contained in a SWB) which indicates that the drum contains debris waste from an approved waste stream (ID-RF-S5300-A). This drum is not part of either BNINW216 or BNINW218 waste streams and, as a result, actions relating to this drum are not reportable under Compliance Order HWB 04-07(CO).

Because of the significant knowledge of the waste stream, the process used to generate the waste, specific information on the drum, and specific information on over 100 drums in the waste stream generated in the same time period, there is sufficient certainty about the drum to assess its potential impact on human health and the environment.

This drum was part of an approved lot covered by headspace gas sampling data and Enclosure 1 shows that the appropriate hazardous waste numbers were assigned. In addition, underground ventilation monitoring covering this room shows that there has been no increase in volatile organic compounds since emplacement of the drum (see Enclosure 2). At estimated emplacement rates, the subject SWB will be isolated from underground ventilation within approximately two months.

The presence of, and the potential impact from, prohibited items is addressed in Enclosure 1. The only prohibited item contained in drum BN10161094 is the presence of liquid in two internal containers totaling less than 0.75 cups (which are most probably water-based solutions). Enclosure 1 rules out the characteristics of ignitability, reactivity, and corrosivity 

### and then addresses the potential impacts as if the liquid were actually corrosive.

CBFO: NT P: DCG: G S:07-1701: U FC5822.00Secretary Curry -2- July 25, 2007

As illustrated, even if it is assumed that the liquid in drum BN10161094 is an acid, the acid would not likely reach the outside of the drum even if it was spilled from its internal containers, and particularly not breach the SWB. The permittees strongly believe that the evidence provided in Enclosure 1 demonstrates that leaving drum BN10161094 in place is protective of human health and the environment.



### Waste Emplacement Strategy

Drum BN10161094 is contained in a SWB in Room 6, Panel 4 with Room 5 being the next room to be filled. In order to provide an opportunity for the New Mexico Environment Department (NMED) to determine if retrieval of the subject SWB is necessary, the permittees have altered the typical waste emplacement process. Before resuming emplacement activities in Room 6, waste will be emplaced in Room 5 to the extent possible. WIPP can only accommodate 20 rows of CH waste in Room 5 in order to allow adequate ventilation to accommodate later access to Room 6. Based on the current inventory of waste on the surface at the site, WIPP can receive 19 additional CH shipments which should provide sufficient CH waste to fill 20 rows of waste in Room 5. It is estimated that the downloading of 20 rows of CH waste to Room 5 will be accomplished within approximately two weeks. Once 20 rows of CH waste have been emplaced in Room 5, waste emplacement activities for Room 6 will resume.

It is estimated that Room 6 will be filled approximately two months after resumption of emplacement of CH waste in Room 6. Once full, Room 6 is projected to contain approximately 168 rows of CH waste. If the decision is made to retrieve the SWB containing drum BN10161094 after Room 6 is full, it will take approximately four months to move the necessary CH waste, retrieve the SWB, and re-emplace the CH waste in Room 6. During this period, disposal of additional CH waste at WIPP will be suspended. Any decision to require retrieval of the subject SWB after the day waste emplacement in Room 5 is suspended, and waste emplacement in Room 6 resumes, would start increasing the impacts on both the ability to retrieve the subject SWB and the ability to continue operations.

In summary, 20 rows of waste can be emplaced in Room 5 without impact to the retrieval plan. As Room 6 is filled, retrieval operations become increasingly difficult up to the point Room 6 is full. Following full emplacement in Room 6(isolation from the ventilation system) retrieval operrations become impractical.



### Corrective Action Plan (CAP) for AMWTP Corrective Action Reoort (CAR) # 28920

Our letter to you on July 20, 2007, provided a description of the occurrence and the associated root cause analysis. Subsequent to the issuance of the letter, the permittees have approved the AMWTP CAR# 28920 corrective action plan identifying actions required for long term program compliance. The CAR (including the CAP) is provided as Enclosure 3. Independent of the AMWTP, the permittees will implement onsite oversight of AMWTP payload assembly and transportation related activities prior to resumption of shipments. The Carlsbad Field Office (CBFO) will transition the transportation authorization at AMWTP to Central Characterization Project (CCP) as quickly as practical as a long term corrective
action.

CBFO: NTP: DCG:GS:07-1701: U FC5822.00Secretary Curry -3- July 25, 2007



### Conclusion As demonstrated in this letter and enclosures, the subject SWB containing drum BN10161094 poses no risk to human health and the environment, and if allowed to remain in WIPP, WIPP will continue to be protective of human health and the environment.

The work associated with retrieval of the subject SWB, if required, poses additional risks of industrial accidents and radiological exposure, which increase with time as the subject SWB in Room 6 has more waste placed in front of it.

The permittees will monitor the implementation and effectiveness of the corrective actions specified in AMWTP CAR #28920 and its required CAP. CBFO will notify NMED when actions are completed that will allow shipments of waste from AMWTP to resume. Prior to final CAR closure, CBFO will verify completion of corrective actions with a surveillance.

If you have questions or require additional information, please contact David Moody at (505)
234-7300.

Sincerely,

David C. Moody, e ic ard D. Raaz, General Manager Carlsbad Field 0 shington TRU Solutions LLC

Enclosure(s)

cc: w/enclosures I. Triay, EM-3 *ED F. Marcinowski, EM-10 ED L. Piper, CBFO ED V. Daub, CBFO ED J. Plum, CBFO ED C. Gadbury, CBFO ED K. Watson, CBFO ED M. Navarrete, CBFO ED R. Patterson, CBFO ED E. Sellers, NE-ID ED P. Divjak, BBWI ED J. Goldstein, NMED ED J. Bearzi, NMED ED S. Zappe, NMED ED J. Reyes, EPA ED T. Peake, EPA ED D. Raaz, WTS ED D. Haar, WTS ED T. Sellmer, WTS ED W. Wiercbicki, WRES ED WIPP Operating Record
CBFO QA File
CBFO M&RC

CBFO: NTP: DCG:GS:07-1701: UFC5822.00