WIPP 700C fan restart test results

The initial test of the WIPP 700-C fan was conducted on Jan 31, 2021. During this test, CEMRC collected air particulate samples at the release point, and several other locations in the surrounding environment, to monitor for any radionuclide releases. The analysis of these samples is now complete and the results for both 24 hours and 5-days counting for alpha emitting radionuclides and 48 hours counting for gamma emitting radionuclides are summarized in Tables below.

 The highlights of the Test are as follows:

• Low activities of ²⁴¹Am and ^239+240Pu were detected at the upper and lower sections of the release point at the fan shroud.
• Activities for identified radionuclides in the upper section were 0.069 Bq (1.88 pCi) for ²⁴¹Am, and 0.008Bq ( 0.50 pCi) for ^239+240
• Activities for identified radionuclides in the lower section were 0.019 Bq (0.21 pCi) for ²⁴¹Am and 0.002 Bq (0.04 pCi) for ^239+240
• Concentrations are consistent with typical Station A readings, which suggests there was no additional contribution of activity from ductwork between Station A and the release point.
• The Am/Pu ratio (10:1) is consistent with sample data from the 2014 unplanned release, thereby ruling out a global fallout or Gnome fallout sources for which the ratios are ~0.44 and ~0.26, respectively.
• Neither Am nor Pu activity was detected at any of the downwind sampling locations monitored during the fan test.
• Both the 24-hr and 5-day counts show essentially the same result, although the 5-day count resulted a lower minimum detectable concentration (MDC) and improved accuracy (counting statistics).
• Highest ²⁴¹Am concentrations of (1.44E-06 pCi/L or 5.22E-03 Bq/m³) were 10,000 times less than average household levels of radon (1.3pCi/L or 48.1 Bq/m³).

²⁴¹Am,  ^239+240Pu and ²³⁸Pu concentrations, Counting time =24 hours

N/d = no detection or activities below minimum detectable concentrations.

²⁴¹Am, ^239+240Pu and ²³⁸Pu concentrations, Counting time =5 days

N/d = no detection or activities below minimum detectable concentrations

Summary of Gamma emitting radionuclides (¹³⁷Cs, ⁶⁰Co and ⁴⁰K) in 700C fan test filters (count time = 48 hours)

N/d = no detection or activities below minimum detectable concentrations