ML19282B445
| ML19282B445 | |
| Person / Time | |
|---|---|
| Issue date: | 01/31/1979 |
| From: | Vassallo D Office of Nuclear Reactor Regulation |
| To: | Rausch D MIRROR INSULATION CO. |
| References | |
| NUDOCS 7903150020 | |
| Download: ML19282B445 (3) | |
Text
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UNITED STATES
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NUCLEAR REGULATORY COMMISSION 3'i h
WASHINGTON, D. C. 20555 UNLh[J
'JAN 31 mg
\\..r.s Mr. D. A. Rausch Manager, Engineering Mirror Insulation Diamor.d Power Division P. O. Box 415 Larcaster, Ohio 43130
SUBJECT:
DIAMCND POWER LETTER REGARDING CWENS-CORNING FIBERGLAS TOPICAL REPORT OCF-l, NUCLEAR CONTAINMENT INSULATION SYSTEM Cear Mr. Rausch:
Your letter of December 6,197F provided information that you wished us to consider prior to completing our review of the subject topical report.
As you now know, our review had been completed and our Topical Report Evaluation had been issued prior to receipt of your letter.
A copy of our Evaluation was sent to you on December 19, 1978.
Even though cur review of the topical report had been completed, we have carefully considered the points raised in your letter and conclude that a revision to our evaluation of the subject topical report is nat needed.
The bases for this conclusion are discussed below.
The NRC staf f's review of the Owens-Corning topical report considered:
(1) release of airborne particles leading to a radiation health hazard in service; (2) stress corrosion cracking of the austenitic stain-less steel surfaces that come in contact with the insulation; (3) deterioration of the thermal properties during normal operation, complicating operation and control of the plant; (4 ) potential f or creating fire hazard in the containment area that could interfere with safe operation of the plant; (5) interference with the emergency spray system in the event of a loss-of-coolant accident; and (6) blocking of pressure relief ports in the event of an accident.
We believe that these are the major safety considerations for this type of i nsul ati on. Our approval of the topical report merely means that the NRC staff has determined that the report is an acceptable reference for licensing actions. It does not imply that the staff believes that it is superior to a competitive product or that it is suitable for every possible application. The licensee bears the primary responsibility for the selec-tion of all components and systems, including thermal insulation.
Many of the points mentioned in your letter were raised a number of years ago by members of the NRC staff and the Advisory Comittee on Reactor Safeguards. This led to the issuance of a number of Regulatory Guides.
79031500do
Mr. D. A. Rausch JAN 3 I 379 As discussed below, one of these, Regulat'ary Guide 1.36, " Nonmetallic Thermal Insulation for Austenitic Stainless Steel," issued in February 1973 deals specifically with thermal insulation; and the others with general requirements for all components regarding shipping, storage, installation, inspection, housekeeping, and quality assurance during operation.
Position C.1 of Regulatory Guide 1.36 cautions:
"All insulating materials should be manufactured, processed, packaged, shipped, stored, and installed in a manner that will limit, to the maximum extent practical, chloride and fluoride contamination from external sources."
The specific criteria that the Nuclear Regulatory Commission uses for evaluation of thermal insulation to be used on austenitic stainless steel are the criteria of Regulatory Position C.2 (Qualification Test) of Regu-latory Guide 1.36.
The Position C.2 Qualification Test requires that a representative insulation sample pass an appropriate stress corrosion cracking test and comp'y with the Regulatory Guide Figure 1 chemical analyses limitation regarding leachable chloride, fluoride, sodium and silicate. The test data and information in the subject topical report show that the Nu'k'on insulation meets the guide and is qualified for use in light-water-cooled nuclear plants in this respect.
As your letter notes, there are a number of potential sources of radio-active or chemical contamination, during construction and operation.
These sources apply to all plant components, not only thermal insulation.
The NRC staff requires that all equipment and components that may affect plant safety be packaged, shipped, stored, installed, operated, and main-tained in a manner to prevent radioactive and chemical contamination.
There are a number of Regulatory Guides that deal with this subject.
Examples of these are Regulatory Guide 1.38, " Quality Assurance Require-ments for Packaging, Shipping, Receiving, Storage, and Handling of Items for Water-Cooled Nuclear Power Plants," Revision 2, issued in May 1977; Regulatory Guide 1.116, "QuMity Assurance Requirements for Installation, Inspection, and Testing of Acc~ snical Ecuipment and Systems," issued in May 1977; Regulatory Guide
.39, " Housekeeping Requirements for Water-Cooled Nuclear Power Plants, ' Revision 2, issued in Septecter 1977; and Regulatory Guide 1.33, " Quality Assurance Program Requirements (Operations),"
Revision 2, issued in March 1978. The NRC staff, as part of our plant specific review, requires that applicants develop a program to implement these Regulatory Guides or their equivalent.
I Mr. D. A. Rausch JAN 3 I spg NRC establishes general safety criteria, sets specific requirements, and provides guidance in the form of Regulatory Guides or NUREG reports.
The NRC staff performs inspections and audits to assure that programs are properly implemented. However, it should be noted that the licensees are the first line of defense to ensure safety of the public. They directly control plant design, construction, operation and maintenance.
The licensees make the basic decision on suitability of specific products and are responsible to see that the plant is operated in accordance with NRC Regulations and in a manner to protect the health and safety of the public.
Operating events can cause contamination. An example of such an event was cited in your letter, namely a fire that occurred on March 6,1973 during non-nuclear testing of Oconee Unit 1.
Wo believe the actions taken following that event are indicative of the actions that NRC would require be taken by the licensee of any plant which experiences a fire or any other event that could have potentially damaged equipment, including insulation. That is, the event would be thoroughly evaluated to determine which components have been or inight have been damaged, the affected or potentially affected ccm-components would be replaced or restored to their initial status, and the affected components and systems would be retested to assure that they were able to perform their intended function.
Based on the considerations discussed above, we believe that our review of Owens-Corning Fiberglas Topical Report OCF-1, " Nuclear Containment Insula-tion System," was performed in an acceptable manner, and covered the major safety concerns. Therefore, we conclude that the topical report is accept-able for referencing on specific applications.
Sincerely, D. B. Vassallo, Assistant Director for Lignt Water Reactors Division of Project Management
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