Report on Testing to Expand the Rotary Mode Core Sampling Operating Envelope
The Tank Waste Remediation System (TWRS) Characterization Equipment Group requested that the Numatec Hanford Corporation--Engineering Testing Laboratory (ETL) perform Rotary Mode Core Sampling (RMCS) Operating Envelope (OE) testing. This testing was based upon Witwer 1998a and was performed at different time periods between May and September 1998. The purpose of this testing was to raise the maximum down force limit for rotary mode core sampling as outlined in the current OE. If testing could show that a higher down force could be used while drilling into a concrete/pumice block simulant while still remaining below the 60 C limitation, then the current OE could be revised to include the new, higher, down force limit. Although the Test Plan discussed varying the purge flow rate and rotation rate to find ''optimal'' drilling conditions, the number of drill bits that could be destructively tested was limited. Testing was subsequently limited in scope such that only the down force would be varied while the purge flow rate and rotation rate were kept constant at 30 scfm and 55 rpm respectively. A second objective, which was not part of the original test plan, was added prior to testing. The Bit Improvement testing, mentioned previously, revealed that the drill bits tested in the OE testing were made of a slightly different metal matrix than the ones currently used. The older bits, a Longyear part number 100IVD/5 (/5 bit), had tungsten carbide mixed into the metal matrix that forms the cutting teeth. The currently used bits, Longyear part number 100IVD/8 (/8 bit), instead have tungsten metal in the matrix and no tungsten carbide. Rockwell C hardness testing showed that the /5 bit was significantly harder than the /8 bit, with values of /8 vs. 8, respectively. The change from the /5 bit to the /8 bit was made immediately after the previous OE testing in 1996 because of sparking concerns with the tungsten carbide in the /5 bit. This difference in hardness between the two bit materials was discovered in the Bit Improvement Testing and was expected to affect this OE testing. The second objective, therefore, was to quantify what affect this change in material had and define the OE, based on the current /8 bit design rather than the old /5 bit design.
- Research Organization:
- NHC (US)
- Sponsoring Organization:
- ENVIRONMENTAL MANAGEMENT (US)
- DOE Contract Number:
- AC06-96RL13200
- OSTI ID:
- 798805
- Report Number(s):
- HNF-3110, Rev.0; TRN: US0205425
- Resource Relation:
- Other Information: PBD: 13 Dec 1999
- Country of Publication:
- United States
- Language:
- English
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