Reducing the Risks of High-Level Radioactive Wastes at Hanford

86 Alvarez
bring the melter pressure back to a normal operating set point (−5 inwc) whenever the
system is outside the normal operating range of −2 to−10 inwc.”
176. U.S. Nuclear Regulatory Commission, Programmatic review of paper entitled
“PRETREAT: Graphical User Interface-Based Spreadsheet Model for Hanford Tank
Waste Pretreatment Processes,” Center for Nuclear Waste Regulatory Analyses, February
4, 2000. Keeping track of every element of pretreatment, alone, at the WTP involves
the use of a complex computer model capable of processing large amounts of data—
involving as many as 20 different worksheets.
177. DOE/ORP-2002-03, p. 6.14 This remains an unresolved issue and according to DOE
“despite pipeline plugging over many years at Hanford, the technologies for removing
plugs are still not well developed.”
178. DNFSB Staff Report,December 10, 2004. “Preliminary calculations indicate that
much of the black and hot cell piping can accumulate hydrogen volumes that are tens
to hundreds of times greater than what has been considered to bea de minimus level.”
179. DNFSB Staff Report, October 29, 2004.
180. Defense Nuclear Facility Safety Board, Letter from John Conway, Chairman to: the
Honorable Spencer Abraham, Secretary of Energy, March 23, 2001. (At the Savannah
River Site, the failure to address proper treatment of secondary sludge wash wastes led
to the clogging of waste evaporators with significant concentrations of highly enriched
uranium—creating criticality safety concerns. Moreover, the inability to process these
led to the reactivation of aged single-shell tanks, which subsequently leaked. For more
than a year, the Defense Waste Processing Plant at SRS was generating and storing a
far larger amount of waste than it was treating.)
181. Letter (with Attachments) from: E. S. Aromi, President and General Manager,
CH2M HILL, to: R. J. Schepens, Manager, Office of River Protection, U.S. Department
of Energy, September 12, 2003. (Hereafter known as Aromi.)
182. NUREG-1747, p. 122. The NRC pointed out that, “For the failed HLW melter, the
great majority of the vitrified waste would have to be removed in order to meet nearsurface
disposal requirements. It was not clear how this could be accomplished for a
melter without bottom drains.”
183. IMAP, p. 2.5.
184. DOE/EIS-0250, February 2002, Appendix A, Table A-41, Comment: DOE estimates
at least 11 failed melters from the Savannah River Site and the West Valley Demonsotration
Vitrification Plant, containing 1,052 tons of radioactive materials, generaing 46
times the decay heat of a HLW canister.
185. DOE/ORP-2002-03, pp. 7.38, 7.27.
186. Ibid.
187. Aromi.