Continued bad weather resulted in delaying Shot UNION until 26 April. MENDER
remained in the Nan anchorage on 17 and 18 April, conducted salvage operations in Area George
on 19 and 20 April, and on 21 April, departed Bikini enroute to Enewetak. The ship returned to
Bikini for approximately one hour on 25 April, prior to getting underwayforits assigned operating
area for Shot UNION.
When Shot UNION wasdetonated at 0605 hours, 26 April, MENDER wassteaming in
an area approximately 35 nmi southeast of Bikini; the ship returned to the lagoon at 1847 hours
and moored alongside LCU-1224 in the Nan anchorage until 2006 hours (although not stated in
the ship's deck log, it is likely MENDER was involved in decontaminating this boat).
At
approximately 2100 hours, MENDERexperienced the samelight fallout from the Shot UNION
cloud that was reported on several other ships anchored nearby. Average topside intensities on
MENDERwere 2 mR/hr at 2100 hours with maximumintensities of 4 mR/hr being reported.
Shownin figure 3.8 is the topside radiation environment on MENDERresulting from Shot
UNIONfallout.
Between 0800 and 1140 hours the following day (27 April), MENDER was involved
with decontaminating "various LCUs"that remained in the lagoonforthe test and thus received
primary (early-time) fallout from Shot UNION. At 1445 hours, MENDER wasdirected to
proceed to Area George to conduct salvage operations, arriving and anchoring there at 1555 hours.
The log is not specific as to which project was supported bythis action, but Project 1.4 did have
two instrument cans moored in the George area. MENDER's anchorage was approximately
1.6 nmi east-southeast of the UNIONsurface zero, which was fortunate, since the general drift of
surface water in the contaminated pool wasto the west and southwest. At about the sametime,
COCOPA was recovering a Project 1.4 instrument can that was moored in Area Dog,
approximately 1.3 nmi southwest of surface zero, and that ship encountered sea water intensities
of 500 mR/hr--section 3.4. Apparently, lagoon water intensities in Area George never approached
the levels they were in Area Dog since MENDERremained anchoredin this area until the morning
of 29 April. Divers aboard MENDERdid conduct diving operations during muchofthe day on 28
April, and could have been exposedto relatively high levels of radiation found in the sub-surface
lagoon water around surface zero.
MENDER returned to the Nan anchorage briefly on 29 April, but at 1320 hours the ship
retumed to the northern anchorage to continue its Project 1.4 support. The deck log states that at
1510 hours, MENDER was “Anchored in area George, Bikini Lagoon,” but the anchor bearings
noted in the log indicate the ship was in Area Dog ("Concrete House on Dog, 063.5°T" implies a
4]