Petersburg Fisheries, Inc. - Executive Summary
EXECUTIVE SUMMARY |
This Risk Management Plan (RMP) is submitted to the United States Environmental Protection Agency (EPA) to meet the requirements of Section 112(r) of the Clean Air Act Amendments of 1990, codified in the Code of Federal Regulation Title 40 Part 68.
Stationary source and chemical of concern
Petersburg Fisheries is located in Southeast Alaska on Mikof Island in the city of Petersburg. The facility is staffed year-round and also employs a large seasonal workforce during the spring and summer months. The plant produces fresh, frozen and canned seafood products, using Anhydrous Ammonia in a closed system as a refrigerant in freezers and cold storage. Ammonia is the safest refrigerant available and has excellent warning properties; it is extremely pungent at levels far below dangerous concentrations. The maximum inventory of ammonia in the plant system is 54,413 pounds. In calculating worst-case and alternative scenarios, efforts were made in all cases to overestimate
rather than underestimate the effects of a release. The plant has been operating safely since refrigeration was installed in 1926.
A worst case scenario is required to be documented in the RMP. Failure of the largest vessel in the system, the High Pressure Receiver (HPR) when filled to capacity would release 7787 pounds of ammonia. The HPR is located in the machinery room. Based on the requirements of the RMP rule, it is assumed that the HPR fails catastrophically, releasing its entire contents over a 10-minute period. To obtain the most conservative assumption, is assumed that the building does not mitigate the rate of release, but the ammonia exits to the outdoors via doors and a ventilation shaft in the machinery room roof. The release is modeled using RMP*Comp(tm) software. Modeling results showed the distance to a toxic endpoint of 140 mg/m3 (200 ppm) to be 1.1 miles (1.9 km). Census data indicates the residential population in the potential radius of re
lease to be 1578.
Alternative Release Scenario
The alternative release scenario for the ammonia refrigeration process is based on a potential hazard identified during the Process Hazard Analysis conducted during documentation of the facility prevention plan. In this scenario, a forklift driver with mast elevated hits a pipe in the overhead in the cold storage complex. The impact causes liquid ammonia piping to crack resulting in a release to atmosphere. No mitigation is considered in the scenario calculations even though the release occurs indoors. The release is evaluated according to the procedures documented in Chapter 4 of the EPA's "Risk Management Program Guidance for Ammonia Refrigeration" (EPA GAR).
Release Prevention Program
Petersburg Fisheries has a prevention program in place to comply with the requirements of the OSHA Process Safety Management (PSM) program, which is designed to prevent accidental releases of ammonia. The PSM program addresses all required elements
including employee participation, process safety information and system drawings, operating procedures, hot work permits, management of change, mechanical integrity, training, pre-startup review, compliance audits, process hazard analysis, contractor safety, incident investigation and emergency response. The system has many safety features built in including high and low level controls and alarms, pressure relief valves, automatic and manually controlled valves and shutoffs, and check valves. Plant personnel responsible for the system have had extensive training including courses conducted by the Ammonia Safety Institute.
Five Year Accident History
Per the requirements of 40 CFR 68.42, facilities must include a five-year accident history for all accidental releases from covered processes that resulted in deaths, injuries, or significant property damage on site or known offsite deaths, injuries, evacuations, sheltering in place, property damage, or environmental damage. There have
been no such accidents at this facility in the past five years.
Emergency Response Program
Petersburg Fisheries maintains a written emergency action plan as part of the PSM plan to facilitate safe response to accidental ammonia releases. The plan identifies personnel designated and trained to conduct the necessary duties during a response. Responsibilities include notification of and communication with local responders and authorities, coordinating and conducting responses, as well as maintenance of emergency equipment and trained personnel. The facility has coordinated its emergency response plan with local authorities and responders and conducts drills periodically to practice responses.