LY 1?  
To: R. E. Durand Address: {Gt-hZ SS
From: H. K. Owen
Subject: Airborne Radioactive Contamination in SHE High Bay during
Reactor Operation.

It is hereby recommended that the SHE be shut down until the sources
of the airborne radioactive contamination in the High Bay are located
and repaired.

Intermittent airborne activity at SRE has long been a problem, but the
primary reason for this reoccmendation was the condition occurring

July 12, 1959 during power run #lh while the reactor was operating at
about l.th. At this time, the High Bey atmosphere became contaminated.
A high volume air sample taken in the High Bay showed an airborne
activity of 3 10?? uc/cc. This concentration is 300 times the maximum
permissible concentration in air for unidentified beta gamma emitters
(MPG 10?9 uc/cc. An attempt to locate the cause of the release Showed
that reactor channel R7 containing a sodium level probe was the primary
source of leakage.

0n subsequent days during this power run, other leaks were found in
reactor channels R29 and R50 and pOSSibly in the Cerrobend seal.

Attempts at identifying this activity here to date been unsuccessful,
however, the airborne contamination levels have in every case Varied
directly with reactor power. EVen if identification of the activity
showed it to have an MPC greater than 3 10?7, repair of the leaks

would be desirable in order to prevent the release of more toxic materials
in the event of a serious fuel rupture.

R. K. Owen
Health Physics Department