ML20151X787

PNO-77-135:on 770722,leakage of Visible Quantities of Chromate Into Outfall Canal Was Identified.Licensee Determined Source of Leakage to Be Concentrates from Radioactive Waste Evaporator

ML20151X787
Person / Time
Site:	Humboldt Bay
Issue date:	07/28/1977
From:	Bidinger G, Higginbotham L NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
To:
References
PNO-77-135, NUDOCS 9809170251
Download: ML20151X787 (1)

Text

pp /> h e'A/ta v > _ (4} /e J/> MbmLIMINARY NOTIFICATION m) n b d e in (Y\ ,

uly 28, 1977 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-77-135

-w This preliminary notification constitutes EARLY notice of an event of POSSIBLE safety or public interest significance. The information presented is as initially received without verification or evaluation and is basically all that is known by IE staff on this date.

FACILITY: Pacific Cas & Electric Company, Humboldt Bay Unit 3 DN 50-133

SUBJECT:

UNTLANNED RELEASE OF LIQUID RADIOACTIVE WASTE On July 22, 1977, leakage of visible quantities of chromate into the outfall canal was identified. The licensee determined the source of the

leakage to be concentrates from the radioactive waste evaporator. The release resulted from the failure of an automatic sump pump system to .

operate. The accumulation of concentrates in the sump were inadvertently -

released thrgugh a leaking valv.e in a.line leading to the yard drain system, which empties into the outfall canal. The evaporator had been started on July 21. The licensee estimat<3 that the total leakage into the outfall canal was 1500 to 2000 gallons. An analysis of a sample showed the concentrates contained a maximum of 0.3 microcuries per milliliter which resulted in a released concentration to Humboldt Bay of about 6 x x 10-8 microcuries per milliliter when diluted with the cooling water from the two operating oil fired plants on the site. An isotopic analysis of the sample showed that most of the activity was cesium-134/137 with cesium-134 representing 10-15 percent of the total cesium activity. The diluted concentration is about 0.5 of the Part 20 limit for cesium-137 in liquids released to unrestricted areas. This event was reportable to the California Regional Water Quality Control Board because the chromium concentration in the release exceeded their limit.

The State limit for chromium is five parts per billion and the release

-J was at about 80 parts per billion. NRC Tech Specs at this facility do E5 not include a limit for chromium. However, a 30 day written report to the NRC is required because of the radioactivity involved.

! U, Media interest has focused on the chemical release, with only mention of /'

the radioactive material involved. The California Regional Water Quality /

Control Board informed Region V that a TV news film crew has asked to accompany their team when they sample biota in Humboldt Bay in the next few days.

k NRC, Region V (Walnut Creek, California) received initial notification cj from the State of California at 5:45 p.m. on July 22, 1977. Region V ;g contacted the licensee immediately thereafter. Additional information,..

including the increased media interest was received by Region V on July 27, 1977.

Contact:

CHBidinger, 1E x27353 LBHigginbotham, IE x27347 Distribution: Transmitted H St J J,1 ;

Commissioner Kennedy C. C. Kammerer, CA G. F. Murphy, JCAE Commissioner Gilinsky S. J. Chilk, SECY H. H. Whiteside, SON H. R. Myers, HCEE Transmitted: MNBB ,f; 2.5 P Bldg .#: 2.3 SS Bldg J.v3 L. V. Gossick, EDO E. G. Case, NRR C. V. Smith, NMSS S . H. Hanauer, EDO

! J. A. Harris, PA W. G. Mcdonald, MIPC Luge (MAIL) E. Volgenau, lE R. G. Ryan, OSP T. J. McTiernan, OIA Region ve _ W3 2_

H. K. Shapar, ELD 9809170251 770728 ***# #

PDR IkE PNO-77-135 PDR