Training plant modifications

Utilities need in house PSA expertise for plant modifications, training, and communications within the utility and with the NRC. 

The team s recommendations (immediate and long term) as to steps that might be taken to prevent any recurrence of incidents of a similar nature. These recommendations should not be confined to such matters as plant modification, but should, if appropriate, embrace training (retraining), assessment of operational procedures, and strengthening of safety measures. Recommendations that improve work systems and conditions make it harder for people to make mistakes. The team should also indicate what... 

This incident, as well as a number of other problems with plant modifications, has been published by Trevor Kletz under the title Some Loss Prevention Case Histories. [8] It is now also available as part of a training kit with 35mm slides, presenters guides, and booklets. The kit is entitled Hazards of Plant Modifications—Hazard Workshop Module 02 and can be purchased from the Institution of Chemical Engineers, Warwickshire, England. I highly recommend it for in-plant training. 

Kletz, Trevor A., A Three-Pronged Approach to Plant Modifications, lass Prevention 10, 1976 pp. 91-98. This material is also available as Hazards of Plant Modifications—Hazard Workshop Module 002 (available as a training kit with slides, booklets, guides, etc., by the Institution of Chemical Engineers, Rugby, England). 

Principles of safe design and operation. Precautions during plant modification. Special considerations with computer-controlled processes. Training of operators. 

Procedure or training failure Failure to revise procedure after changes to work practice after plant modifications... 

In addition to normal recertification requirements, the restart training program for operations personnel includes training on major plant modifications, procedures, changes to administrative controls, teamwork and diagnostic skills, applied fundamentals, communications, emergency response actions, technical specifications, and many other topics. A list of the major subjects taught each cycle is contained in Attachments 1 and 2. 

Management personnel also received an overview in subject areas such as fire protection, leak-before-break, seismic, and communications. The training overviewed the reactor restart plan and items such as plant modifications and upgrades, changes in Technical Specifications, changes in operating procedures, and the purpose of the linking document. 

Paskall (25) has recently reviewed the various modifications to the Claus process that result in optimum sulfur recovery efficiency. Overall plant conversion efficiencies in the range of 97% were considered to be the upper limit at the beginning of the 1970 s (26). While this is a very respectable conversion efficiency for an industrial process the unrecovered 3% in a 2,000 tonne/d sulfur plant represents 60 tonnes/d of sulfur lost, mainly to atmosphere as 120 tonnes/d of SO2. Modifications to the four stage Claus converter train however, can raise overall conversions to over 98.5% thus halving the sulfur loss to the plant tail gas. This either reduces environmental impact or the load on tail gas desulfurization units that will be discussed later. 

This incident illustrates that we must train our mechanics to seek approval of any changes in job scope, before they independently initiate alternate approaches. We cannot assume that because we employ qualified craftsmen and graduate engineers, they will never carry out repairs with foolish or improper methods. Chemical plants must be continually vigilant for unwise modifications. 

A hasty modification can result in an accident, as discussed in Chapter 6. To address the problems of one-minute modifications, chemical plant management must persistently encourage employee awareness and train their employees about the potential dangers that can be created by the quick, inexpensive substitutions. It is essential that well-maintained engineering and equipment specifications are readily available. Changes which might include improper substitutes (such as incompatible materials of construction) or improper procedures should be reviewed by a third party. However, this is sometimes easier said than done in the sometimes hectic pace of maintaining maintenance and production schedules. 

Modifications to plant or process System for Control of changes in raw materials Formal approval for plant/process changes Hazard and operability study prior to implementation (repeat when in use) Updating of all operating instructions, notices, procedures Removal/isolation of obsolete plant/lines Control of changes in personnel (see training)... 

In an ideal world, an easy-to-contact, responsive modifications man would be available for questions generated in Operations, Engineering, and Maintenance. This modifications man could be a Process Safety Engineer, Loss Prevention Engineer, or a mechanical or chemical engineer who has been trained in chemical process safety. Preferably, this individual would be an on-site plant employee, but he could be a company regional engineer, a property insurance consultant, or a contractor. The modifications man must understand basic loss-prevention principles of proper layout. 

The experience reported above represents 95-97% sulfur to sulfuric acid conversion efficiencies. Sulfuric acid plants of 200 tonne/day capacity are common and some large singe-train plants are now operating on the scale of 4,000 tonne/day [17], so even these high conversion efficiencies are not enough to avoid local emission problems. Thus, the U.K. has a requirement of 99.5% containment of the sulfur burned as a feedstock, while the U.S.A. s 99.7% sulfur dioxide to sulfur trioxide conversion efficiency [56]. With modern process modifications and emission control devices in place, these requirements are being met. 

The Army has sought to build in the process of learning by experience to avoid accidents where possible, and to avoid repeating them in any case. The centerpiece of this effort, the programmatic lessons learned (PLL) database, is admirable as a personnel-training tool but requires further modification to improve its accessibility (see Chapter 4). Despite considerable effort in plant design and personnel training, mistakes have been made and problems have occurred in the chemical demilitarization process. 

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