Instrumentation Report No. 2: identification, evaluation, and remedial actions related to transducer failures at the spent fuel test-climax

Abstract

The Spent Fuel Test-Climax (SFT-C) is a test of the feasibility of safe and reliable short-term storage and retrieval of spent fuel from commercial nuclear reactors. In support of operational and technical goals of the test, about 850 channels of instrumentation have been installed at the SFT-C. Failure of several near-field instruments began less than six months after emplacement of 11 canisters of spent fuel and activation of six thermally similar simulators. The failed units were linear potentiometers (used to make displacement measurements) and vibrating wire stressmeters (used to maKe change-in-stress measurements). This report discusses the observed problems and remedial actions taken to date.

Spent fuel test - Climax: technical measurements. Interim report, fiscal year 1981

“…Nine gauges of the new design were reinstalled in place of failed units from June [16][17]1981. All of these new units appear to be functioning normally to date (Patrick, Carlson, and Rector, 1981).…”

“…The stressmeters were removed from the two vertical holes (6 units) and one end of one horizontal hole (3 units). Other units were left in place to avoid damaging units that were still functioning (Patrick, Carlson, and Rector, 1981).…”

“…Weldment Weldment Figure 10-11. Use of thin, stainless cups in new gauge (after Patrick, Carlson, and Rector, 1981). available from ESR files are also considered reliable.…”

“…A series of field and laboratory tests were then undertaken, which indicated the possibility of chemical vapor action on the potentiometer resistive element (Patrick, Carlson, and Rector, 1981). Based on this assessment, the head assembly covers were removed to vent such vapors.…”

Spent Fuel Test-Climax: technical measurements data management system description and data presentation

“…The Q/A Plan referred to in the last objective of the preceding section requires thorough documentation of these activities, so the source of the parameters used, the algorithms applied, background information, and references will be given in same detail. Much of the needed reference information is contained in a relatively few documents: The Technical Concept (Ramspott et al, 1979), a series of Project Interim Reports (Carlson et al, 1980;Patrick et al, 1982;Patrick et al, 1983;Patrick et al, 1984a), and three reports on instrument installation and performance (Brough and Patrick, 1982;Patrick, Carlson, and Rector, 1981;Patrick, Rector, and Scarafiotti, 1984c). It is assumed that the reader is familiar with the Livermore Time Share System (LTSS), in particular, the XPORT utility for file transport and storage, and its directory structure (Smith and Belles, 1981).…”