While many of these programs are driven by 29CFR1910.147 (Control of Hazardous Energy), energy control procedures at a power plant are drawn from 29CFR1910.269 (Electric Power Generation, Transmission and Distribution). The two standards closely parallel one another to the point that measures taken to comply with 1910.147 are deemed to be in compliance with the hazardous energy control procedures of 1910.269(d). One difference is that the power generation standard provides for the use of tags in cases where it is not possible to use a lock or when it has been demonstrated that a tagging system will provide protection equal to that of a lockout program.
Kewaunee uses a sophisticated tagout program called eSOMS™, a software system from Tech-Assist, Inc. designed to assist in managing plant operations. eSOMS includes modules such as narrative logs, qualifications and scheduling, and an equipment database, but the clearance component provides the framework for the tagging program.
The first step in the tagging process is to determine the scope of the tagout; i.e., which systems or components need to be isolated and tagged out to complete the job safely. This is done using the work package for the particular task, previous tagouts, plant drawings and any other supporting documentation. The tagout is then built online using eSOMS and the interfacing within its databases. Four key individuals, including the job lead and operations supervision, must approve the tagout before any tags are hung.
Once the tagout has been created, a tag hang list is generated and the appropriate tags printed. Three different tags are used in the process. A red Danger Tag is used to protect employees from death or serious injury. The key element to the process is that no one under any circumstances is permitted to operate equipment that is tagged with a Danger Tag, nor can anyone remove a tag except for Operations.
A yellow Caution Tag informs workers of the status of a component. It may provide hazards and consequences of operating the component but does not provide any protection for the work force. The third tag used is a green Operating Permit, which is always placed along with a physical lock. This tag is primarily used when worker protection is required but the component (such as a motor-operated valve) must be manipulated during the course of the work. The only person with a key to this lock is the job lead and it is his/her responsibility to ensure that everyone involved in the work is in the clear when the equipment is operated.
Danger Tags are hung with a 50-lb. red nylon tie strap; Caution Tags and Operating Permits with black ties. Should a tie be found on a component without a tag, Operations must be notified immediately. The tags themselves are made from a strong material that is resistant to tearing and damage by the elements. A computer generates the tags using permanent ink to satisfy the legibility requirement.
Once the tagout is approved for hanging, trained operators place the components in the specified configuration (i.e., "closed," "off," etc.) and hang the corresponding tag. This is done in the sequence instructed by the tag hang list. The operator will release any stored energy associated with the component, as instructed, and verify that the release was successful. Human Performance tools such as self-checking and procedure compliance are used to ensure that the tagout is configured correctly. If at any time the operator is uncertain about the information provided, he/she will stop and resolve the issue prior to proceeding.
After the tags are hung, a second operator will do an independent verification of the tagout to ensure that the tags were hung on the proper components, the components placed in the desired configuration and that the energy was released. The job lead will also walk the tagout down prior to the work commencing to make certain that the tagout was placed such that it provides the protection necessary to perform the task safely.
All employees and contractors are trained in the use of the tagging program to the extent that they will be involved. Essentially everyone receives training that will allow him or her to work under a tagout. Others receive instruction in tagout oversight, hanging tags, preparing tagouts, etc.
All tagouts are listed in the eSOMS system. Different screens display an array of information about each tagout including the types of tags, the components on which they are hung, the placement configuration (off, closed, etc.), the hanging and removal sequences, the various verifications and approvals and, certainly not least, who is actively working under the protection of (signed on to) the tagout.
No one is allowed to perform work that involves a tagout until they have been properly trained and have "signed on" to the tagout. The "signing on" is viewed as placing one's "virtual lock" on the system. It involves logging onto eSOMS, locating the appropriate tagout number and entering an ID and password. Once personnel have signed on to the tagout, it cannot be lifted or reconfigured until all persons have signed off.
Another feature of eSOMS is that it allows tagouts to share tags. When a tag is generated, it is assigned a sequential number and notes the component to which it is assigned as well as the position it is placed in while the tag is hanging. If another tag series involves that component, it uses the same tag and tag number provided the desired position of the equipment is the same. In other words, the system obviously will not allow the same component to be concurrently positioned "on" for one tagout and "off" for another. Only one tag will hang on a given component at a time.
When work is completed, all workers previously signed on to the tagout must sign off and, in essence, remove their "virtual locks" from the system. Once this step has been completed and verified by the job lead, the work package will be returned to Operations, who will lift the tags and reposition equipment according to the tag list. If a component is still part of another tagout that is actively being worked, that will be so noted in the system and will not appear on the tag removal list.
Safety truly comes first at Dominion and Kewaunee Power Station. The eSOMS system allows plant employees to effectively and efficiently manage the hazardous energy control program and maintain the high level of performance that is expected from a safe, world-class nuclear operator. ip
Roger W. Buttke is a Senior Instructor—Nuclear, at the Dominion-Kewaunee Power Station in Wisconsin.