ML19351F655
| ML19351F655 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 09/26/1980 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| References | |
| NUDOCS 8101130675 | |
| Download: ML19351F655 (1) | |
Text
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UNITED STATES e
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E REGION V
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o, 1990 N. CALIFORNIA BOULEVARD SulTE 202, WALNUT CREEK PLAZA WALNUT CREE K, CALIFORNIA 94598 7
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September 26, 1930 Docket do. 50-312 Sacramento Municipal Utility District P. O. Box 15330 Sacramento, California 95813 Attention:
Mr. John J. Mattimoe Assistant General fianager Gentlemen:
This Infomation tiotice is provided as an early notification of a possioly significant matter.
It is expected tnat recipients will review tne infomation for possible applicacility to tneir facilities.
No specific action or response is requested at tnis tice.
If further dRC evaluations so indicate, an IE Circular or dulletin will be issuea to recommend or request specific licensee actions.
If you have questions regarding Inis matter, please contact the Director of cne appropriate WRC Regional Office.
Sincerely, k /mzY l
R.11. Engelken i
Director i
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Enclosures:
l 1.
IE Infomation flotica Jo. d0-34 l
2.
Recently Issued IE Informacion l
docices cc w/ enclosures:
R. J. Rodriguez, SMUD L. G. Schwieger, SMUD l
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SSINS No.: 6835 Accession flo. :
8008220239 IEIN 80-34 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT HASHINGTON, D.C.
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September 26, 1980 l
IE Information Notice No. 80-34: BORON DILUTION OF REACTOR COOLANT DURING STEAM GENERATOR DECONTAMINATION l
Description of Circumstances:
Recently two instanccs of boron dilution of the reactor coolant system have occurred.
Both cases were a result of high pressure washing of the steam generator tube sheets for decontamination to reduce the radiation levels during eddy current testing and related steam generator work.
i On May 29, 1980, Trojan Nuclear Plant miscalculated the excess boric acid required to offset the demineralized water used in washing the tube sheets.
This resulted in the boron concentration of the primary coolant being reduced to less than the minimum required by the Technical Specifications.
The dilu-tion was, however, expected since the wash water was allowed to enter the reactor vessel through the nozzles.
On July 5,1980, San Onofre Unit 1 inadvertently diluted the reactor coolant boron concentration when the high pressure demineralized flushing water leaked l
by a dislodged nozzle seal. The inflatable seals had been installed to prevent i
the non-borated water from entering the reactor.
The resulting boron concentra-tion was greater than required for shutdown margin, but the positive reactivity added was in excess of that allowed by the Technical Specifications.
l This Information Notice is provided to identify potential problem areas involved with decontaminating specific areas of steam generators.
It is expected that I
recipents will review the potential hazards involved and consider increased monitoring of 1) inflatable seal performance, 2) vessel level, and 3) boron concentration.
Increasing the boron concentration of the primary system prior to performing any decontamination activities or using borated water for washing should also be considered.
It is expected that recipients will review this information for possible applicability to their facilities.
No specific action or response is requested at this time.
If you have any questions regarding this matter, please contact j
the Director of the appropriate Regional Office.
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IN 80-34 September 26, 1980 RECENTLY ISSUED IE INFORMATION NOTICES Information Date of flotice No.
Subject Issue Issued to 80-33 Determination of Teletherapy 9c M/IM All teletherapy Timer Accuracy (G3) licensees 80-32 Clarification of certain 8/12/80 All NRC and agreement requirements for Exclu-state licensees sive-use shipments of radioactive materials 80-31 Maloperation of Gould-8/27/80 All light water reactor Brown Boveri Type 480 facilities holding OLs volt type K-600S and or cps K-00fl 600S circuit breakers 80-30 Potential for unaccept-8/19/80 All boiling water reactor able interaction between facilities holding power the control rod drive scram reactor OLs or cps.
function and non-essential control air at certain GE BWR facilities 80-29 Broken studs on Terry 8/7/80 All light water reactor turbine steam inlet facilities holding flange power reactor OLs or cps
- Supplement to Hotification of 7/29/80 All holders of reactor 80-06 significant events at and near-term OL ~
l operating power reactor applicants facilities 80-28 Prompt reporting of 6/13/80 All applicants for and reouired information holders of nuclear power to NRC reactor cps 80-27 Degradation of reactor 6/11/80 All pressurized water coolant pump studs reactor facilities holding power reactor OLs or cps 80-26 Evaluation of contractor 6/10/80 All Part 50 licensees QA programs
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- Operating Licenses or Construction Permits n
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