[Global] [EXTERNAL] Request for Recommendations – Cavity Decontamination Equipment and Techniques
Parlone Richard
richard.parlone at edf-energy.com
Thu Nov 6 08:00:55 EST 2025
Hi Mike,
We found on dry fuel cask cleaning (Holtec HI-TRAC) and cavity wall plus floor cleaning that pressure washer sprays were not enough, we needed to agitate or scrub the surface. We clean our cavity walls up to 9 feet, all floors.
Our equipment of choice looks very similar to what Joe has posted below:
* Pressure washer lance heads topped by rotating hinged nylon brushes. We buy about 10-15 of these for an outage. Price is about $60 each (UK price shown), company is Nilfisk. Operational Experience is to secure the couplings with a suitable bonding agent (e.g. Loc-Tite) and to teach the teams to start the pressure washer spray and brush rotation away from the wall, floor or cask surface, then move the brush to the surface. Excellent decon factor.
[cid:image001.png at 01DC4F1D.1F0ACE40]
* Floor cleaners identical to Joe’s post but using the rotating pressure washer heads and brush surface. Good for large areas, we have several different sizes because of the floor furniture (cavity blanks, ISI gallery covers, etc). We have some wall cleaners like this and are experimenting the best option between the brushes noted above and the larger surface area cleaner. Combination has definitely reduced cleaning time and dose over the years. Units couple to the standard pressure washer lance and have two rotating spray heads underneath.
[cid:image002.png at 01DC4F1D.5FC00D60]
Kind regards,
Richard
Richard Parlone
Head of Radiological Protection
Technical & Safety Support Department
EDF Nuclear Operations
Sizewell B Power Station, Suffolk, United Kingdom IP16 4UR
T: (+44) (0)1728 65 3750 (Internal 718 3750)
Proud Sponsors of Alzheimer’s Society
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From: Global <global-bounces at list.rpalara.org> On Behalf Of Coughlin, Joseph J: (Constellation Nuclear) via Global
Sent: 06 November 2025 11:58
To: Michael J Griffin <mjgriffin at aep.com>; global at list.rpalara.org
Subject: Re: [Global] [EXTERNAL] Request for Recommendations – Cavity Decontamination Equipment and Techniques
Morning Mike, We use a similar pressure washer but have a rotary spray surface cleaner attachment to use vs traditional standard tip. This is not exact one we use but similar. Takes some force to hold to walls but gets a lot more surface area then just the tip. Hope this helps…
i
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Morning Mike,
We use a similar pressure washer but have a rotary spray surface cleaner attachment to use vs traditional standard tip. This is not exact one we use but similar. Takes some force to hold to walls but gets a lot more surface area then just the tip. Hope this helps………Thx Joe
[cid:image005.png at 01DC4F1D.1F0ACE40]
From: Global <global-bounces at list.rpalara.org<mailto:global-bounces at list.rpalara.org>> On Behalf Of Michael J Griffin via Global
Sent: Tuesday, November 4, 2025 2:22 PM
To: global at list.rpalara.org<mailto:global at list.rpalara.org>
Subject: [EXTERNAL][Global] Request for Recommendations – Cavity Decontamination Equipment and Techniques
EXTERNAL MAIL. Do not click links or open attachments from unknown senders or unexpected Email.
Subject: Request for Recommendations – Cavity Decontamination Equipment and Techniques
We are currently evaluating opportunities to enhance the efficiency and effectiveness of our cavity decontamination process. At present, we utilize a 3500 PSI pressure washer with a standard tip to decon the cavity walls and floor. For optimal performance, the tip must be positioned within 2 inches of the surface; otherwise, multiple passes (typically 4–6) are required to achieve acceptable results.
This limitation significantly impacts productivity, particularly when cleaning vertical surfaces up to 6 feet high and approximately 60 feet in length, which can take several hours. Additionally, the cavity floor presents challenges due to the presence of NI detector covers and nozzle access covers, which are elevated several inches above the main floor. These obstructions prevent the use of conventional floor-cleaning equipment such as buffers or scrubbers.
We are seeking input from other sites or teams regarding equipment, pressure washer tips, and attachments that have proven effective in similar conditions. Our goal is to improve decon efficiency, reduce time, and minimize dose.
Any recommendations or lessons learned would be greatly appreciated.
[cid:image006.png at 01DC4F1D.1F0ACE40]
Michael J. Griffin | ALARA planner
mjgriffin at aep.com<mailto:mjgriffin at aep.com> |
cook nuclear plant
1 Cook place, Bridgman, MI 49106
| 269-465-5901 *7547 | cell 269-449-2437
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