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OFP CE OF 

AIR AND RADIATION 

Dr. Dave Moody, Manager 

Carlsbad Field Office 

U.S. Department of Energy 

P.O. Box 3090 

Carlsbad, New Mexico 88221-3090 

Dear Dr. Moody: 

This letter provides the results ofthe foliow-up inspection at the Carlsbad Field 

Office (CBFO) that U.S. Environmental Protection Agency's (EPA or we) conducted in 

December 2007. As a result of this inspection EPA determined that CBFO has 

adequately resolved EPA concems speeific from the EPA inspection of the W IPP (Waste 

Isolation Pilot Plant) Waste Information System (WWIS) conducted in January 2004 

(EPA-CBFO-W WIS-01.04-24). 

In ?Vlarch 2004, EPA issued a letter transmitting the inspection report (EPA Air 

DocketNo: A-98-49, II-A4-39). The letter stated that ". .. The WWIS is also adequate 

for the reporting of derived quantities, such as the total transuranic (TRU) alpha activity 

and TRU alpha concentration, pending resolution of the findings and concerns described 

in this report. EPA identified three (3) coneerns, all of which require a response from 

DOB. DOE should respond in writing to the three (3) concerns within 6 weeks of receipt 

of the enclosed report." These were not responded to within the 6 weeks, but EPA was 

able to evaluate and determine that site-specific waste data entered in the W WIS by the 

sites were appropriately modified to reflect changes made by the W WIS database 

manager to address the 2004 concerns. However, the formal closure of the concerns 

could only be obtained using the W WIS system maintained by the W WIS database 

manager in Carlsbad. 'I'his was accomplished in December 2007. 

During EPA's December 2007 follow-up inspection in Cartsbad, EPA gathered 

the objective evidence to verify changes to the relevant W WIS algorithms had been 

satisfactorily changed, and the waste data have been correctly reported. The enclosed 

inspection report describes the concerns and their resolution following review of 

objective evidence. 

internetAdGress(URL)® http://w~.epa_gov 

Recycled/Recyc4able 0 Printed with Vegetable Oil6ased Inks on SQO% Postconsumer, Process ChSorine Pree Recycled Paper 
If you have any question, plea.secontact Rajani Joglekar at (202) 343-9462 or Ed 

Feltcorn at (202) 343-9422. 

Sincer Iv, 7

.~,~~ ~ 

Juan Reyes, Director 

Radiation Protection Division 

Enclosure 

cc: Electronic Distribution 

Vernon Daub, CBFO 

Casey Gadbury, CBFO 

Courtland Fesmire, CBFO 

Norrna Castaneda, CBFO 

Ava Holland, CBFO 

Martin Navarrete, CBFO 

Dennis Miehls, CBFO 

Brian Littleton_ BPA 

Steve Zappe, NMED 

Allison Pangle, CTAC 

Wayne Ledford, CTAC 
ENCLOSURE 

EPA Follow-up Inspeetion at W WIS, December 2007 

Background: 

On December 5, 2007, E PA conducted a follow-up inspection to verify that the changes 

made to address I:PA concerns are teehnically adequate. "I'he purpose of the meeting was 

to discuss and close three concerns that originated from EPA Inspection No.EPA-CBFOW WIS-01.04-24 in 2004 that remained open. The EPA inspector met with the Carlsbad 

Field Office (CBFO) staff and the WIPP Waste Information System (W WIS) personnel 

to review objective evidence that addressed EPA's concem from the January 2004 W WIS 

inspection. EPA and CBFO personnel had discussions regarding these concerns on 

severai occasions and the only component that prevented closing the concerns was 

inspection of the objective evidence that addressed each concern. Attendees at the 

December 5, 2007 meeting were as follows: 

EPA Concerns and Resolution: 

Tlie three EPA concerns identifred during the January 2004 inspeetion are listed below, 

followed by the resolution for each. 

EPA Concern No. I— The total TRU activities reported tor eight of the ten inner 

containers in SRTP00114 are based not on the aetivities of the individually reported 

radionuclides, but on a MDC assigned to that container. In these instances, the total TRU 

activity reported for the inner container is significantly greater than that calculated by 

summing the reported activities of the individual TRU radionuclides. Between the other 

two inner containers in TDOP SRTP00114, the total TRU activity reported for inner 

container SR252852 is 15% greater than the sum of the aetivities of the individual "I RU 

radionuclides. 

No. 1 Resolution — This concern had two components, the first of whieh was specific to 

the Imaging Passive-Active Neutron (IPAN) Non Destructive Assay (NDA) system at the 

Savannah River Site (SRS). 'T'he IPAN's software used the Lower Limit of Detection 

(LLD) value for 24 'Am as an actuai estimate of a waste drum's 241 Am content and 

ineluded it in the calculation of the drum's TRli Alpha Activity (TAA), which was 

incorrect. This component was isolated to the IPAN and was addressed previously and 

was not within the scope of the Deeember 5, 2007 meeting. "I'he second component of 

this eoncern was addressed by revising DOE-WIPP-02-3122, the CII TRU Waste 

Aeceptance Criteria (WAC), 6ppendi_x E, in accordance with the August 4, 2003 CBFO 
poticy statement Management of TRUAlpha Activity Concentratfon. The essence of this 

ehange is to prevent the reporting of quantitative LLD estimates to the WWIS, as 

specified in WIPP Waste Information System IJser's Manuai, DOE/CBFO 97-2273, 

Revision 12, WWIS Ver. 5.4a, Section 9.4, and incorporating these changes in the 

W WIS. This change adequately addresses EPA's concern and this concern is closed. 

EPA Concern No. 2— The method used to calculate the uncertainty in the TRtJ alpha 

aetivity (TAA) concentration of an overpack, including TDOP and S WB, is technically 

incorrect. When a derived quantity is the product (or quotient) of two independent 

random variables, the relative uncertainty of the derived quantity is the square root of the 

sum of the squares of the reported relative uncertainties of'the two independent random 

variables. The absolute uncertainty of the derived quantity is calculated by multiplying 

the quantity by its relative uncertainty. The ealculation of the absolute uncertainty in the 

TAA eoncentration of the overpack as the square root of the sum of the squares of the 

reported absolute uncertainties in the total TRLT activity concentration of each of the 

inner eontainers, performed by the W WIS, is technically incorrect. The latter calculation 

eannot be shown to be mathematically equivalent to the fonner, and evidence indicates 

the quantitative differences in the results of the two methods are significant. Based on 

the reported uncertainties in the totai TAA and mass of waste in the payload container, 

reported uneertainties in the TAA are significantly greater than uncertainties expected. 

No, 2 Resolution — To address this concern the WAC was formally modified to refleet 

the lack of requirement to report the uncertainty associated with TAA concentration, 

including overpacks, "IDOPs and SWBs. "This is stated in DOE-WIPP-02-3122, Revision 

0, dated May 17, 2002, Section 3.3.2, page 3-11. This WAC requirement is essentially 

the same in Revision 6.0, dated November 15, 2006. Accordingly, the uncertainty for 

TAA concentration is not calculated, making a discussion regarding the calculation's 

correctness irrelevant. The section of'software code that addresses this was reviewed and 

V ersion 4.17 states that the field for TAA concentration is optional. The data base 

modification was performed in aecordance with Proeedure WP 08-NT.04, WIPP Waste 

Information System Conftguration Management and Sofnvare Ouality Assurance 

Program. This concern is closed. 

EPA Concern No. 3 — The W WIS does not have adequate quantitative checks to verify 

that data concerning the radiological constituents of waste emplaced in the WIPP is selfeonsistent. At a minimum the following conditions should be met for payload containers 

as a whole, and individualiy for all of the inner containers included in an overpack: (1) 

the total TAA reported must be equai, wifli some reasonabie allowance for round-off 

errors, to the sum of the individually reported TRIJ radionuelide aetivities; (2) the TAA 

concentration reported must be equal, with some reasonable allowance for round-off 

errors, to the total TAA divided by the mass of waste in the container; and (3) the 

reported activity of each radionuclide should, with some reasonable allowance for roundoff errors and uneertainty in the radionuclide's specifie activity, agree with the reported 

mass of that radionuclide. 
No. 3 Resolution —The WIPP Waste Information System User's Vianual, DOE/CBFO 

97-2273, Revision 12, WWIS Ver. 5.4a, Section 9.5 documents an edit/limit check that is 

performed to compare the reported TAA with the TAA calculated based on the sum of 

the individually reported TRIJ radionuclides. The difference between the reported and 

calculated values is limited to five pereent (5%), as specified in Figure 9-7 of the WAC 

Limits Reference Table. An example ofthe reference table is provided in Section 9.8, 

Figure 9-6, 7RUAlpha Activiry and TAAC Data F'ields. WWIS Version 4.16 requires a 

5% agreement for each of these three quantities: the activity concentration of the TRII 

alpha radionuclides; the total TRU alpha aetivity; and, radionuclide activity relative to 

mass. These checks are implemented as documented in DOEICBFO 97-2273, and this 

practice adequately addresses EPA's concern. This concern is closed. 

Conclusion: 

Upon evatuating objective evidence showing changes to address the EPA concerns and 

discussion with the WWIS staff, EPA concludes that W WIS has adequately resolved ail 

three EPA concerns.