DEFENSE NUCLEAR FACILITIES SAFETY BOARD

April 22, 2011 

MEMORANDUM FOR: T. J. Dwyer, Technical Director

FROM: B.P. Broderick and R.T. Davis 

SUBJECT: Los Alamos Report for Week Ending April 22, 2011 

Transuranic Waste Operations – Safety Basis: This week, the discovery of new information related to 

the Area G Drum Venting System (DVS) prompted LANL management to declare a Potential Inadequacy of 

the Safety Analysis (PISA). Startup of the DVS is intended to reestablish the capability to safely vent the 

thousands of unvented drums currently stored above and below ground at Area G in preparation for final 

disposition. Earlier this year, LANL management declared implementation of the safety basis revision that 

covered DVS operations in advance of a Contractor Readiness Assessment (CRA), which ultimately failed 

to demonstrate adequate readiness to begin venting operations. 

The implemented safety basis analyzes a drum deflagration event and the resulting overpressure challenges 

to DVS components. The analysis assumes the deflagration occurs in a drum with a 12% headspace gas 

concentration of hydrogen and also assumes the failure of internal DVS valves designed to contain blast 

pressure, allowing the deflagration overpressure to be vented into a greater volume. In the course of 

pursuing a question raised during the recent CRA, LANL personnel recognized that the assumptions related 

to hydrogen concentration and the failure of the blast valves may not be conservative. Higher hydrogen 

concentrations and actuation of the blast valves, both of which are credible, would lead to a more energetic 

deflagration confined to a smaller volume. This situation produces calculated pressure conditions inside the 

DVS chamber that are greater than those analyzed in the current safety basis, which prompted the PISA. 

LANL personnel are developing a path forward to address the PISA and evaluating the impact of these 

issues on the DVS startup schedule. 

Integrated Work Management (IWM): Based on several events that occurred between late-2010 and 

early-2011 involving issues with work planning/execution and conduct of operations, the laboratory deputy 

director chartered a senior team to develop a comprehensive understanding of obstacles and issues 

negatively impacting LANL’s IWM program. This team recently completed their review and identified the 

following four Judgments of Need (JON) along with recommendations for corrective actions to address 

these JONs: 1) LANL needs to accelerate full implementation of conduct of operations within craft and 

vendor work planning and execution; 2) LANL needs to strengthen the subcontractor technical 

representative program; 3) LANL needs to develop and implement an effective tool to evaluate operational 

performance that provides indicators for issues that require broad-based corrective actions; and 4) LANL 

needs to develop a mechanism to evaluate major organizational changes that may impact institutional IWM 

implementation. The team recommended nineteen specific corrective actions to laboratory senior 

management to address the identified JONs. 

Seismic Safety: This week, the site office forwarded the Board’s April 8th letter on issues with the 

computer software SASSI (A System for the Analysis of Soil-Structure Interaction) to LANL and requested 

a summary of the site’s use of this code, information on code versions used, the basis for software quality 

assurance and any other information relevant to responding to the Board’s letter. The site office directed 

LANL to respond to this request within three weeks. 

Plutonium Facility – Seismic Safety: The site office memorandum discussed above also requests LANL 

to provide plans for identification and anchorage of critical equipment within Plutonium Facility gloveboxes 
(e.g., furnaces that could contribute to post-seismic fire initiation). These plans will be included in the 

overall project execution plan for upgrades in response to Board Recommendation 2009-2.