ML20003E314
| ML20003E314 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 03/16/1981 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| References | |
| NUDOCS 8104020864 | |
| Download: ML20003E314 (1) | |
Text
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m['o UNITED STATES g
NUCLEAR REGULATORY COMMISSION o
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REGION V o
1990 N. CALIFORNI A BOULEVARD e
SulTE 202, WALNUT CREEK PLAZA e,,,e WALNUT CREEK, CALIFORNIA 94596 March 16, 1981 9
Docket No. 50-312 e-110
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0; Sacramento Municipal Utility District
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ff P. O. Box 15830 E,,"94/?p 7
Sacramento, California 95813 g
I Attention: Mr. John J. Mattimoe Assistant General Manager 4'
Gentlemen:
4 This information notice is provided as an early notification of a possibly significant matter.
It is expected that recipients will review the information for possible applicability to their facilities. No specific action or response is requested at this time.
If further NRC evaluations so indicate, an IE circular or bulletin will be issued to recommend or request specific licensee actions.
If you have questions regarding this matter, please contact the
' Director of the appropriate NRC Regional Office.
Sincerely, Dirdctor f
Enclosure:
IE Information Notice No. 81-07 cc w/ enclosure:
R. J. Rodriguez, SMUD L. G. Schwieger, SMUD
SSINS No.: 6835 Accession No.:
8011040267 e
IN 81-07 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C. 20555 March 16, 1981 IE Information Notice No. 81-07:
POTENTIAL PROBLEM WITH WATER-S0LUBLE PURGE DAM MATERIALS USED DURING INERT GAS WELDING Description of Circumstances:
Recent experiences with water-soluble purge dam materials at several nuclear construction sites have shown the need to develop welding procedures that address the potential for thermally decomposing the purge dam material during inert gas welding or post-weld heat treatment operations.
Specifically, polyviryl alcohol film manufactured by Chris-Craft Industries was the purge dam material used at these construction sites.
The decomposition of this purge dam material at elevated temperatures causes the material to lose its solubility in water. As a result, the purge dam material cannot be completely dissolved durir.g subsequent piping system flushing and cleaning operations.
The failure of this material to completely dissolve could cause significant problems during reactor plant operation.
- Specimens'of polyvinyl alcohol film were recently obtained from the Mono-Sol
- Division of Chris-Craft Industries and tested at Franklin Research Center (FRC)- to determine, among other things, the threshold temperature at which the material becomes insoluble in water. The results of this test program indicate that'(1) the solubility of the purge dam material in water rapidly approaches:zero if the material is heated and held at temperatures in excess of 300F; (2) the purge dam material hardens and becomes difficult to break if subjected to temperatures in the range of 300F to 400F, and becomes brittle if heated to 450F; and (3) purge dam material heated above its threshold temperature is not soluble in commonly used laboratory solvents.
The inde-pendent testing laboratory (FRC) therefore concludes that the Mono-Sol poly-vinyl alcohol film will not dissolve during aqueous flushing of the system if. the material' has been heated to temperatures in excess of 300F.
Recommended Actions for Holders of Operating Licenses and Construction Permits:
It is reconinended that all welding operatioits involving polyvinyl alcohol purge dam materials be governed by procedures that require the material to
- be, located-in areas that are sufficiently. removed from heat so that the
- temperature lof th'e material does not reach 300F.
No written response to this information notice is required.
If you require additional information with regard to this subject, please contact the
- appropriate NRC. Regional Office.
Attachment:
Recently issued'IE Information Notices
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Attachment IN 81-07 March 16, 1981 RECENTLY ISSUED IE INFORMATION NOTICES Information Date of Notice No.
Subject Issue
' Issued to 81-06 Failure of ITE Model 3/11/81 All power reactor
.K-600 Circuit Breaker facilities with an OL or CP 05_
Degraded DC System at 3/13/81 All power reactor Palisades-facilities with an OL or CP 81-04 Cracking in Main Steam 2/27/81-All power reactor Lines facilities with an OL 81-03 Checklist for Licensees 2/12/81 All power reactor i
Making Notifications of facilities with an Significant Events. in OL Accordance with 10 CFR 50.72 1
81-02
- Transportation of 1/23/81 All Radiography Radiography Devices licensees 81-01
'Possible Failures of 1/16/81 All power reactor General. Electric Type facilities with an HFA Relays OL or CP. 45 Potential Failure of 12/17/80 All. PWR facilities BWR Backup Manual Scram with_ an OL' or CP -
Capability 80-44
. Actuation of ECCS in the 12/16/80 All PWR facilities Recirculation Mode While-with an OL or CP in Hot Shutdown
! ailures of the Continuous 12/5/80
. All power reactor 80-43:
F Water Level Monitor for
' facilities with. an
~
the Scram-Discharge Volume OL or CP at Dresden Unit'No. 2 80-42 Effect of Radiation on 111/24/80~
All power' reactor Hydraulic Snubber Fluid facilities with an OL or CP q
OL = Operating. Licenses-CP =. Construction Permits.
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