scaffold used for radiation sheilding and kept in place more than 90 days? How to handle the issue ?

[prasanta34]

If a scaffolds used for radiation shielding are required to be kept inside the plant for greater than 90 daus, how to handle the issue in the plant licensing space and show we should address it as "temporary alteration"? How we address scaffold in 10CFR 50.59 Screening? UFSAR does not address scaffold"?

 

[jpankask]

The UFSAR should not address scaffolding, as it is typicallynot part of the plant design. However, if scaffolding needs to remain installed in the plant for greater than 90 days, it is no longer temporary. It has now become a temporary modification, or a permanent design, depending on the purpose. It sounds like you are using the scaffolding to hang your shielding blankets. The 50.59 screening is the method of evaluating whether you need to seek NRC approval for this "modification". You need to evaluate the potential effect on Safety Related equipment and also the seismic qualification of the scaffolding. At our plant, we complete a configuration change package, with requisite 50.59 screening. If the scaffold needs to remain in place for a very long time (i.e. will not be removed by your next UFSAR update), you also DO need to have it added to your UFSAR, because it has now become plant design (even if "temporary"). Because this is a very cumbersome process, at our plant we normally direct that the scaffold be removed prior to 90 days, unless it is absolutely critical to remain longer, in which case we ask that the group request for a permanent/engineered design change be pursued. Maintenance has a database that tracks installed scaffolds and alerts them when the 90 days is approaching.

One other small caveat that is easy to miss...if you know on day 1 of installing the scaffold that it will be installed for greater than 90 days, you should completing the 50.59 screening immediately. It's hard to prove, but that can be fodder for a violation.

 

[racookpe1978]

Don't "game" the system.

Follow the intent of the rules: If a structural component is going to be "permanently installed" - and not installed and removed temporarily as for an outage or for repairs or temporary shielding - classify it appropriately and STUDY IT officially as a permanent part of the plant.

 

[EnergyMix]

If the scaffolding is used to provide a support for shielding, then you also need to evaluate the shielding and its effects. If you need the shielding to be there, then you should process the permanent modification.

Want to know the do's and don'ts of Eng-Tips? Read FAQ731-376.
English not your native language? Looking for some help in getting your question across to others or understanding their answers? Go to forum1529.