Beatty LLRW Site Event LLW Forum Spring Meeting Park City, Utah April 2016

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Beatty LLRW Site History LLRW facility operated from 1962-1992 USE operated site for State of Nevada License transferred to State in 1997 Regular cap inspections performed by NDHHS - periodic cap subsidence repairs done as required Located adjacent to USE’s RCRA-permitted hazardous waste treatment & disposal facilities.

Beatty LLRW Event Incident occurred on Sunday, 10/18/15 Site security personnel heard “popping noises” from inside restricted area Local USE personnel responded and captured cell phone video from secure area. State Dept of Health Notified immediately

US Ecology Video

Beatty LLRW Event Fire started in base of crater. Allowed to burn out without intervention Total Event Time: ~12 hrs Governor Sandoval initiated Nevada emergency response Rapid response teams deployed to site (State, Federal, and USE) US Hwy 95 closed for nearly 48 hours Response team included teams from NV State Agencies, NV National Guard, LVPD Armor Team, EPA, and DOE. Hwy 95 was initially closed due to flooding but was kept closed until LLRW event was appropriately resolved.

Beatty LLRW Event Photo courtesy of NDPS

Initial Response No gamma dose rates >BKG observed (surface & DOE RML flyovers) No alpha or beta contamination measured around crater or from expelled waste Samples from expelled waste showed high pH =13 Offsite lab analysis of samples C-14: 131 pCi/g (max) 200,000+ ppm sodium

Annotated Site Map N US Ecology deployed a radiological response team to the site on Monday 10/19. Extensively surveyed the site and found no observable gamma radiation and no beta/gamma removable contamination. Samples were collected from residues of ejected waste. Full rad/RCRA suite of analyses ran. Only Sodium (>200k ppm) and C-14 found (130 pCi/g max). 1. Note subsidence area on map for next photo. Figure courtesy of NDPS

Root Cause Analysis Nevada DPS led investigation Water infiltration and reaction with Na cited as root cause Confirmed that Na was received at Beatty from Bureau of Mines Water intrusion due to cap subsidence (1.86” Oct rainfall vs 0.28” avg) 1000 yr event! Burn pattern consistent with Na reaction and fire We do not know for sure if cap subsidence began after first 1+” inch rainfall event or after an additional 0.5” that fell in the 24 hours prior to the event. Plausible that both events contributed to the subsidence and water intrusion into Trench 14.

Beatty LLRW Event Subsidence Crater Photo courtesy of NDPS

Trench 14 Subsidence This subsidence area is in Trench 14 and directly west of crater. Which is ‘upgradient’ from a surface water runoff perspective. US Ecology Photo

Next Steps Site temporarily restored. Exhumed waste placed back in trench and covered. NDHHS developing Long-Term Action Plan Research into landfill receipts and content Cap design and construction improvements (in consultation with NRC, DOE, and US Ecology) Enhanced landfill surveillance and measurements

Interim Site Restoration Steel support beams and 80-mil liner over crater with sandbags (Trench 14) Photos courtesy of NPDS and NDHS

Interim Site Restoration Overpack drum support and 80-mil liner over Trench 14 subsidence Photos courtesy of NPDS and NDHS

Trench 14 Crater Repairs Photos courtesy of NPDS and NDHS

Trench 14 Subsidence Repairs Photos courtesy of NPDS and NDHS

Contact Information Joseph J. Weismann, CHP Vice President, Radiological Programs (208) 319-1634 Joe.Weismann@Usecology.com