Augmented evaluation of the false criticality alarm at Idaho Chemical Processing Plant

Technical Report · Fri May 01 04:00:00 EDT 1992

OSTI ID:5183159

The Office of Self-Assessment (DP-9), Defense Programs (DP) began to monitor a Criticality Alarm system (CAS) failure occurrence at the Idaho Chemical Processing Plant (ICPP) shortly after January 11, 1992, when a false trip of the CAS in building CPP-601/602 caused a plant evacuation. Building CPP-601/602 contains the uranium fuel reprocessing denitration system, which was not operating at the time of the CAS failure occurrence. At that time DP-9 and Westinghouse Idaho Nuclear Company (WINCO), the Department of Energy (DOE) operating contractor, believed that this event may represent a potential generic safety concern for other DOE facilities. This false criticality alarm activation did not pose a significant danger to the health and safety of the public or to ICPP employees. Once the CAS was activated, the ICPP was evacuated per procedures. However, false CAS actuations are undesirable. The CAS system should be extremely reliable because of the dangers associated with criticality events and the potential for accidents and injuries resulting from prompt process termination and building evacuation. The Office of Self-Assessment then formed an Augmented Evaluation Team (AET) for an on-site diagnostic assessment of the CAS at ICPP. The AET's on-site evaluation process included briefings by ICPP management, discussions with pertinent technical supervisors and managers, an examination of relevant CAS documentation, physical examination of failed equipment, and a walk-through of the ICPP CAS. The AET judged that the most probable direct causes of the CAS failure were the heat induced failure of a low voltage power supply combined with the concurrent and/or prior failure of its back-up nickel cadium (NiCad) battery located in the CAS. The battery was not adequately maintained. These judgments are consistent with WINCO's analyses.

• Research Organization: USDOE Assistant Secretary for Defense Programs, Washington, DC (United States). Safety Diagnostic Div.
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• OSTI ID: 5183159
• Report Number(s): DOE/DP-0101T; ON: DE92014825
• Country of Publication: United States
• Language: English

Related Subjects

050800* -- Nuclear Fuels-- Spent Fuels Reprocessing
054000 -- Nuclear Fuels-- Health & Safety
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
ALARM SYSTEMS
CRITICALITY
DATA ACQUISITION
ELECTRONIC EQUIPMENT
EQUIPMENT
EVALUATION
FAILURES
FUEL REPROCESSING PLANTS
IDAHO CHEMICAL PROCESSING PLANT
MODIFICATIONS
NATIONAL ORGANIZATIONS
NUCLEAR FACILITIES
RELIABILITY
SAFETY ANALYSIS
TEMPERATURE EFFECTS
US AEC
US DOE
US ERDA
US ORGANIZATIONS