PNO-V-88-010, on 880207,licensee Inadvertently Drained Approx 1,100 Gallons of Slightly Contaminated Borated Water from Borated Water Storage Tank During Testing.Testing Suspended Until Investigation & Further Corrective Action Completed

PNO-V-88-010:on 880207,licensee Inadvertently Drained Approx 1,100 Gallons of Slightly Contaminated Borated Water from Borated Water Storage Tank During Testing.Testing Suspended Until Investigation & Further Corrective Action Completed

ML20196D005
Person / Time
Site:	Rancho Seco
Issue date:	02/08/1988
From:	Dangelo A, Miller L NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
To:
References
PNO-V-88-010, PNO-V-88-10, NUDOCS 8802160314
Download: ML20196D005 (1)

PRELIMINARY NOTIFICATf0N OF EVENT OR UNUSUAL OCCURRENCE--PNO-V-88-10 Date 02/08/88 This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. The information presented is as initially received aithout verification or evaluation and is basically all that is known by Region V staff on this date.

FACILITY: SACRAMENTO MUNICIPAL UTILITY DISTRICT Emergency Classification RANCHO SECO UNIT 1 __ Notification of Unusual Event DOCKET NO. 50-312 Alert HERALD, CA Site Area Emergency General Emergency X Not Applicable

SUBJECT:

SPILL FROM CONTAINMENT SPRAY HEADER AT RANCHO SEC0 On February performing 7,1988,ofatthe a portion about Loss1:00 am (PST),

of Offsite Powerwith testthe p(lant in cold shutdown, while LOOP),thelicensee inadvertently drained approximately 1100 gallons of slightly contaminated borated water from the borated water storage tank (BWST) through the two lower rings of the containment spray header inside the reactor building. The incident occurred when a safety features actuation signal opened the reactor building spray system isolation valves as a planned part of the test. As planned, the spray pumps did not start (their breakers were lined up in the test position). However, contrary to the test plan, a manual valve in one train of the spray system was open when it should have been shut for the test. This allowed borated water to drain from the BWST (+47 ft, elevation) to the two lower spray rings (-2 ft. and +38 f t elevation). Operators detected this condition after about thirty minutes, while restoring the normal valve lineup for containment spray.

The licensee had resumed testing on February 6,1988, following a meeting with Region V management on February 5, 1988, and completion of corrective action from the incidents ehich occurred during the LOOP testing on February 3, 1988 (PN0-V-88-08). Subsequent to the latest incident, the licensee has resuspended testing until an investigation and further corrective action are completed. The resident inspectors were onsite during the latest incident, and are monitoring the licensee's investigation and corrective action.

The licensee issued a press release on February 7,1988. There has been media interest.

This information is current as of 11:00 am, PST, February 8,1988.

CONTACT: L. Miller A. D'Angelo FTS 463-3869 209-748-2791 DISTRIBUTION MADE BY 5520 TO: FAX TO:

Date W/ff Time eco ven Date Time Chainnan Zech EDO RI INP0 Comm. Roberts - AE00 RII NSAC Comn. Bernthal PA0 RIII LICENSEE  :

Comm. Carr SLITP RIV RESIDENT INSPECTOR  ;

Comm. Rogerc NRR HQS OPERATIONS OFFICER i SECY NMSS CA ARM MAIL T0:

PDR OI DCS(Original)

OGC OIA DOT:(Trans. Only. Applicable State)

ACRS RES GPA g21gi4 800208 RV FORM 211 l P NC--V- 88-010 PDR Revised: 8/19/87 l l

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