Legitimization of New Paint-and-Varnish Coatings for Facilities Using Nuclear Energy: A Regulatory Checklist of 7 Documents
Abstract. The use of a new paint-and-varnish or protective coating that is not included in industry lists at facilities using nuclear energy (FUNE) requires completion of an established procedure for documented confirmation of conformity. This article presents a sequential list of seven documents required for approval of the material by Rostechnadzor construction control. It examines requirements for the product passport, qualification test reports, the conclusion of the Lead Materials Science Organization (LMSO), the certificate of conformity, and inclusion in the Consolidated List.
General Principle
When accepting new materials at an NPP, construction control follows the principle of 'presumption of non-applicability': if a material is not included in approved industry lists of standardization documents, it is considered not approved for use. The legitimization process is built as the sequential formation of an evidence base, from the manufacturer's documentation to a legally significant approval by Rostechnadzor. The seven mandatory elements of this system are listed below.
Purpose: to record the basic characteristics of the material and confirm its compliance with technical specifications (TU).
Content: the passport must include information about the intended use, chemical composition, physical and mechanical properties (yield strength, modulus of elasticity, corrosion resistance), as well as reports of initial factory tests. A reference to duly approved technical specifications is mandatory.
Key parameters checked by the inspector:
• Safety class of the building structure under NP-041-22.
• List of aggressive media with which the material will come into contact.
• Operating-temperature range (for NPPs it is wider than for general industrial equivalents).
• For coatings in strict-regime zones, compliance with GOST 26825-86 (requirements for chemical resistance and appearance after exposure).
2. Guideline Document (Assessment of Impact on FUNE)
Purpose: documented justification that the use of the coating does not compromise the external or internal safety of the facility using nuclear energy.
Content: the document is prepared by the lead materials science organization or another accredited organization and contains calculations and justifications in the terminology used in mechanical engineering for nuclear power plants. It relies on industry federal rules and regulations (FNiP), which impose stricter requirements for fire, radiation, and mechanical resistance than general-construction GOST standards.
3. Qualification Test Report (Testing under PNAE G-7-010-89 and Related Standards)
Purpose: to confirm the coating's resistance to impacts simulating actual NPP operating conditions.
Content: for steel structures, the basic document is PNAE G-7-010-89 or its updated versions (NP-105-18). For paint-and-varnish coatings, analogous test reports are used to verify compliance with:
• GOST R 51102-97 (decontaminability of coatings);
• GOST 26825-86 (resistance to decontamination solutions);
• GOST 27708-88 (resistance to decontamination formulations).
Mandatory types of testing:
Resistance to aggressive liquid media: 5% nitric acid solution and 5% sodium hydroxide solution.
For power units with VVER reactors, an additional solution containing 1.600% boric acid, 0.300% KOH, and 0.025% hydrazine hydrate.
Decontamination factor (ability to be washed free of radioactive contamination) must be confirmed by a numerical value.
Surface condition after exposure: smooth, monolithic, with no blistering, peeling, or loss of adhesion.
4. Conclusion of the Lead Materials Science Organization (LMSO)
Purpose: scientific and technical expert review confirming that the properties of the new material are equivalent to or better than those of previously approved analogues.
Regulatory basis: the obligation to involve the LMSO is established in nuclear-industry regulatory documents, including PNAE G-7 and industry standards. Without the LMSO conclusion, the technical documentation is not accepted for review by Rostechnadzor.
Report requirements (according to Appendix No. 4 to NP-010-16, Rules for Localizing Safety Systems of Nuclear Power Plants):
The report must include:
• chemical composition of the material;
• heat-treatment modes (if applicable);
• strength, elasticity, and thermal-conductivity values;
• characteristics in the temperature range from 20°C to Tmax, as well as at values exceeding Tmax by 25°C, 50°C, and 100°C.
5. Certificate of Conformity (Legal Approval by Rostechnadzor)
Purpose: the final legal document certifying that the product complies with federal rules and regulations in the field of nuclear energy use.
Issuance procedure: the certificate is issued based on analysis of the entire collected package (product passport, qualification test reports, LMSO conclusion). The list of products subject to mandatory certification in this system was approved by Rostechnadzor Order No. 277 dated July 21, 2017.
Legal significance: the existence of the certificate gives construction control grounds to admit the material for installation at the facility.
6. Decontamination Report (Confirmation under GOST R 51102-97)
Purpose: documentary evidence that the coating can be cleaned of radioactive contamination using standard means without destroying its own structure.
Mandatory nature: the report is required for all coatings introduced into the strict-regime zone (SRZ) of an NPP.
Test method: the coating is applied to a sample, contaminated with radioactive indicators, and then washed using the decontamination-solution formulations specified in GOST 26825-86 and GOST R 51102-97. The decontamination factor is measured and compared with the standard. The supervisory authority verifies that the formulation complies with these standards specifically, not with arbitrary manufacturer specifications.
7. Inclusion in the Consolidated List (Industry List of Principal Materials)
Purpose: final recognition of the material in the industry regulatory framework, allowing general contractors to order it under the standard procedure without repeated approval.
Procedure: after successful completion of all previous stages, the material is included in the Consolidated List of standardization documents in the field of nuclear energy use or in the industry list of principal materials. Inclusion is formalized by a special protocol of the lead industry materials-science body.
Consequences: after inclusion in the list, the material is considered legitimized, and its use at subsequent facilities does not require repeating the full procedure; reference to the list is sufficient.
Conclusions and Recommendations
The use of a new protective coating at facilities using nuclear energy is possible only if a complete documented trail exists, including the seven elements listed above. The recommended strategy is to prepare the document package at the pre-supply stage, before installation work begins. A properly prepared factory passport, PNAE G-7 qualification test reports, LMSO conclusion, and certificate of conformity make it possible to pass Rostechnadzor construction control without delays.
TechAtomStroy assists in preparing documentation packages for the legitimization of paint-and-varnish and protective coatings for the requirements of a specific facility. To obtain consultation and support for qualification testing, send the material specification through the feedback form on the website.
*This material was prepared on the basis of an analysis of the following regulatory documents: NP-041-22, NP-010-16, PNAE G-7-010-89, GOST R 51102-97, GOST 26825-86, and Rostechnadzor Order No. 277.*