ML20008E376
| ML20008E376 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 09/26/1980 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Kay J YANKEE ATOMIC ELECTRIC CO. |
| References | |
| NUDOCS 8010270456 | |
| Download: ML20008E376 (1) | |
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g NUCLEAR REGULATORY COMMISSION 3.
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,o' KING OF PRUSSIA, PENNSYLVANIA 19406 September 26, 1980 Docket No.'50-29 Yankee Atomic Electric Company ATTN: Mr. James A. Kay Senior Engineer - Licensing 25 Research Drive Westborough, Massachusetts 01581 Gentlemen:
The enclosed IE Information Notice No. 80-34, " Boron Dilution of Reactor Coolant During Steam Generator Decontamination" is forwarded to you for information.
No written response is required.
If you desire additional information regarding this matter, please contact this offica, i
Sincerely, o
Boyce H. Grier Director
Enclosures:
1.
IE Information Notice No. 80-34 2.
List of Recently Issued IE Information Notices CONTACT:
E. G. Greenman (215-337-5267) cc w/encls:
H. Autio, Plant Superintendent J. E. Tribble, President l
l 8010270 k
SSINS No.:
6835 Accession No.:
8008220239 IEIN 80-34 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 September 26, 1980 IE Information Notice No. 80-34:
BORON DILUTION OF REACTOR COOLANT DURING STEAM GENERATOR DECONTAMINATION Description of Circumstances:
Recently two instances 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.
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 baron 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 by a dislodged nozzle seal.
The inflatable seals had been installed to prevent the non-borated water from entering the reactor.
The resulting baron concentra-tion was greater than required for shutdown margin, but the positive reactivity added was in excess of that allowed by the Technical Specifications.
This Information Notice is provided to identify potential problem areas involved with decontaminating specific areas of steam generators.
It is expected that recipients 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 the Director of the appropriate Regional Office.
IE information Notice No. 80-34 September 26, 1980 RECENTLY ISSUED IE INFORMATION NOTICES Information Subject Date Issued to Notice No.
Issued 80-33 Determination of 9/15/80 All holders of Teletherapy Timer a teletherapy Accuracy license 80-32 Clarification of 9/12/80 All helders of Certain Requirements an NRC or Agreement for Exclusive-use State License Shipments of Radioactive Materials 80-31 Maloperation of Gould-8/27/80 All holders of Brown Boveri 480V-Type a power reactor K-600S and K-Don 600S OL or CP Circuit Breakers 80-30 Potential for Unaccept-8/27/80 All holders of able Interaction a BWR power reactor Between the Control OL or CP Rod Drive Scram Function and Non-essential Control Air at Certain BWR Facilities 80-29 Broken Studs on 8/7/80 All holders of Terry Turbine a power reactor Steam Inlet Flange OL or CP Supplement Notification of 7/29/80 All holders of a to 80-06 Significant Events power reactor OL at Operating Power and near term OL Reactor Facilities applicants 80-28 Prompt Reporting 6/13/80 All applicants of Required Information for and holders To NRC of a power reactor l
construction permit 80-27 Degradation of Reactor 6/11/80 All holders of Coolant Pump Studs a pressurized water power reactor OL or CP