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NSLS ESH Highlight #17

Changes in Radiation Protection Procedures

Date: August 26, 1999
Editor: R. Casey, T. Dickinson, N. Gmür

Since December 1998, changes in radiation protection procedures have been occurring to improve radiological practice and control of radioactive materials. Further changes in procedures can be anticipated throughout the rest of this calendar year. Most changes have not significantly impacted the NSLS – one important change has been made recently that everyone should take note of.

1. A Radiation Work Permit (RWP) is required for entry into Radiation Areas.

Radiological postings have been changed in several locations on the NSLS floor to reflect this change in requirements. At BNL, the posting of a Radiation Area will typically read:

"Radiation Area - RWP required for Entry". At the NSLS, the signs are usually further qualified to identify a particular condition during which the radiation area exists, e.g. "Radiation Area during VUV injection". An individual may enter such a posted area without an RWP if it can be verified that the qualifying condition does not exist, e.g. injection is not underway. However, if a sign or radiation barrier must be moved, this may be done only by a member of the Radiation Control Division, even if the Radiation Area is not in effect at the time.

Entry into the posted area when the radiation area exists requires that a formal work-planning document (an RWP) be completed and approved prior to entry. Take note of the new postings that are now on the floor. If you foresee a need now or in the future to enter these areas under the identified conditions, get together with a member of the NSLS Safety Staff and together we can prepare the RWP before you need it. In the past we have been able to accommodate work in these areas by scheduling it when there is no radiation such as during maintenance periods or by dumping the beam a few minutes before the 12:30 fill in the VUV ring to allow a short task to be done. We expect to continue this practice. Note that Rad Worker I training is required for anyone working under an RWP, so this training must be completed before such work.

There are two locations where we have requested a variance to the RWP requirement:

  1. the cross-over above the x-ray tunnel which becomes a Radiation Area when injection into the x-ray tunnel occurs, and
  2. the walkway within the x-ray tunnel which becomes a Radiation Area when beam from the Booster strikes the x-ray beam stop.

In both these areas, a person can walk through the Radiation Area in going from one location to another and receive very low doses that are not recordable on our TLD badges. An RWP will not be required for walking through these locations when a Radiation Area exists.

However, if some type of work other than a walk-through is necessary when the Radiation Area exists, a RWP would be required.

Please take note of this change in requirements. Entry into these areas without a RWP would be a significant violation of BNL radiological requirements and could result in disciplinary actions to the offender, and penalties to NSLS and BNL.

2. Monitoring of material removed from the Accelerator structures

Although not a new requirement, signs have also been posted at exits from the NSLS Linac, Booster, X-ray ring, VUV ring and the ATF to reinforce the requirement that materials removed from the machine tunnels be surveyed for radioactivity. Tables have been provided at each location for the material to be left at when it is brought out of the accelerator enclosure area. Following survey by members of the Radiological Control Division; the item, if free of radioactivity, can be released and used in any area. If the material is found to be radioactive, it will be labeled and tagged. Such material must remain tagged and must be stored or worked on only within "Controlled Areas". Workers planning maintenance on equipment inside the ring enclosures should discuss these plans with a member of the Radiological Control Division staff so that survey of any items to be removed can be arranged with minimum delay and inconvenience.

Residual radioactivity can be induced in materials that have been in close proximity to high energy electron beam loss points. At NSLS, the induced radioactivity is not very high (typically a maximum of a few mRem/hr at contact), but the material must be labeled and controlled.

If you have questions regarding these requirements, please contact any member of the NSLS Safety Staff, or any member of the Radiological Control Division staff assigned to NSLS:

Chris Weilandics, x2593, pager 6208
Rudy Zantopp, x5565, pager 6210
Marlon McAvoy, x6389, pager 9102