DELTA Field Umpire

Reading here

– mSv/h (digits for the umpire only)

Waiting for position…

Plume and position

Follow me

Air sample

Flow (L/min)

Duration (min)

Bkg (cpm)

No sample taken yet.

Meteorology

Weather source

Override (use the Information Board values)

Wind from (°)

Speed (m/s)

Stability

Blank = the exercise met table. Values entered here replace it until cleared (only if the Information Board shows something different).

Exercise weather table

Time and test position

Testing / desk use

Clock offset: days

hours

minutes

Or set exercise time now to (hh:mm)

Test position: distance (km)

bearing from site (°)

Exercise time = phone clock + offset, so the plume develops in real time while you test (e.g. set 09:50 to watch the release start). Negative values go back. The offset is remembered on this phone until cleared. A test position replaces GPS until cleared.

Centre line now (for the umpire)

Basis

The meter is drawn as a Ludlum Model 9-4 (SI): linear 0 – 5 face with a range switch (0–50 µSv/h, 0–500 µSv/h, 0–5 mSv/h, 0–50 mSv/h); the needle pegs above full scale. Exercise readings are below 0.012 mSv/h, so the 0–50 µSv/h range is the one to use. The map shows the plume to 2.5 standard deviations either side of the centre line. Map data © OpenStreetMap contributors.

RASCAL 4.3.4, Exercise DELTA best-estimate case D. Scenario Rev 0y: containment air leak through the 1 RIS 101 WD penetration into the Fuel Building from 09:55, through DVK (iodine filters on) to the 65 m stack. Modelled as the case D release (failed-fuel coolant, I-131 eq. 7.7E10 Bq/m³, 140 m³/h), the release behind Cue Cards 8 and 9.

Centre-line values come from RASCAL runs for each stability class, scaled by wind speed. Beyond 5 km they are extended along the 3–5 km slope. The lateral fall-off is Gaussian with the Briggs open-country plume width, as on Cue Card 8. The release falls with time (about 20 % per 15 min after 10:40), as on Cue Card 8.

Air samples follow KFG-EG-010 Rev 4: iodine counts give the adult thyroid committed dose rate (factor 3.8); particulate counts give the committed effective dose rate (factor 0.025).

Default weather is the simulated exercise met from Scenario Rev 0y section 3.2 (as on the Information Board), following the exercise clock. Blue lines on the map are the survey lines of Cue Cards 8b – 8d. From 10:15 to 11:20 the plume axis is held at 028° as on Cue Card 8 (the Board's wind is 205 – 208°), so the app gives the cue-card readings on the survey lines. If the Information Board shows different values on the day, enter them under Override. These are exercise cues, not measurements.