JAEA-Testing-2011-007.pdf:46.74MB - 日本原子力研究開発機構

(4) Set a time schedule of the work
JAEA-Testing 2011-007
JAEA-Testing 2011-007
Set a time schedule of the work using the form, “Record 5: Time schedule of the
work” based on information obtained in the precedent steps such as dimension of
swimming pool (volume of pool water), number of available materials and tools,
available number of staffs and overall schedule.
Approximate times that are assumed to require for each task are shown below.
【Briefing of the procedures】 1 hour
Briefings are held before starting the procedures. It will include explanation to
all of the program members to inform about the entire procedures and detailed
explanation to each task group members about practical method and note to be
aware of.
【Securing of a discharge flow path (removal of sediment)】 0.5 day
Remove mud and fallen leaves accumulated in the discharge flow path.
【Radiation survey before work】 3 hours
Sample swimming pool water at predetermined sampling points, and measure
radioactivity concentration with a radioactivity detector. If the radioactivity
detector is not available at the site, time required to transport the samples
needs to be added to the above time.
【Discharge of supernatant】 1 day
When the radioactivity concentration in the pool water is lower than the
criteria for discharge, discharge the supernatant with engine pumps, while
taking care of not to pumping up mud or fallen leaves accumulated on the
bottom.
【Treatment in 1 ton plastic tank】 1.5 hour/one tank
When the radioactivity concentration is higher than the criteria for the
discharge, pump up the pool water together with mud and fallen leaves
accumulated on the bottom. It takes 20 minutes to feed zeolite, flocculant and
neutralizer. Leave at rest 30 minutes to allow sufficient precipitation. It takes
15 minute for discharging the supernatant and 15 minutes for recovery of the
precipitate on the bottom of the plastic tank.
- 123 -
- 123 -