Nuclear power plants have been continuously constructed in Korea during the three decades since Kori Nuclear Power Plant, the first nuclear power plant built in Korea, started commercial operation in 1978.
Currently, 17 units of PWR types and 4 units of pressurized heavy water reactor (PHWR) types are in operation in Korea, and the Shin-Kori, Shin-Wolsung and Shin-Ulchin Nuclear Power Plants are currently being constructed – evidence that nuclear power has become an important energy source in Korea.
ASME BPVC has been applied to all existing nuclear power plants, with the exception of Ulchin Plants Units 1 and 2, where RCC was applied and Wolsung Units 1 through 4, where CSA was applied. Accordingly, KEPIC has adopted the technical requirements of ASME BPVC without modification, following the spirit of safety of ASME BPVC, and has customized the requirements of system and operation for the local environment.
Thus developed, KEPIC has been applied to all new nuclear power plants under construction, starting with Units 5 and 6 of Ulchin Nuclear Power Plant, and it is also being applied to the construction of the UAE nuclear power plant.
As the global demand for nuclear power increases rapidly during this current nuclear renaissance, a demand for a comparative analysis of major nuclear power plant design codes has been identified, with the focus being the major regulatory institutions of nuclear power countries. A comparison has been conducted on ASME (USA), RCC (France), JSME (Japan), KEPIC (Korea), CSA (Canada), and ENES (Russia), and the differences in codes between each SDO and ASME 2007 edition have been compared and analyzed.
This section contains the results of a comparison of ASME and KEPIC in relation to the safety of nuclear power, Class 1 pressure vessels, piping, pumps, valves, etc. based on a study made over the last several years. As a result, it was found that there was no difference in technical requirements, with the exception of system requirements, and it has been concluded that there are no technical issues in applying equipment manufactured in accordance with KEPIC to nuclear power plants where ASME is applied.
KEA would like that the result provided in this report can be utilized as important data that will enable a better understanding of the differences in the nuclear power plant design codes of the various regulatory institutions of each country, equipment manufacturers, construction companies and certification institutions, and that technical exchanges between SDO of each country can become more active, and that collaboration to promote the safety of nuclear power plants will be increased based on this result.
6.2 Introduction
In accordance with the agreement among SDOs participating in TG MDEP, differences of ASME BPVC were noted and closely analyzed with regard to Class 1 components. In the analysis of differences, administrative requirements as well as technical requirements were included. As for the technical requirements, KEPIC-MNB and ASME BPVC Section III Div. 1 NB were compared. For administrative requirements, KEPIC-MNA and ASME BPVC Section III Div. 1 NCA were compared. With the base of requirements in the ASME BPVC 2007 Edition, the corresponding KEPIC 2005 Edition – 2008 2nd Addendum – was compared in summary. The requirements of KEPIC-MN deal with piping, pumps and valves, as well as Class 1 pressure vessels, the same as
BPVC. The administrative requirements deal with the differences in the parts where KEPIC follows Korean laws and regulations much like ASME follows U.S. laws and regulations.
The comparison results were divided into four groups in accordance with the agreement among SDOs and the bases are as specified in the general introduction of this report (Section 6.1).
6.3 Preliminary Paragraphs and Scope Presentation
This section includes a comparison of the requirements on ASME NB 1000 and KEPIC-MNB 1000, a general requirement among the Class 1 equipment requirements of ASME and KEPIC.
ASME NB 1000 specifies various requirements, including aspects of construction, temperature limits, and jurisdictional boundaries related to Class 1 equipment design and manufacturing. KEPIC has basically the same configuration and contents as ASME NB, but a few differences are mentioned below.
KEPIC has a sole certification and stamping system that is different than ASME but is very similar (see Table 39).
KEPIC demands that KEPIC-MI (equivalent with ASME BPVC Section XI) be met for in-service inspection in MNB 1110.
Also, KEPIC mentions that the rules of KEPIC-MN may be used for HVAC (refrigerator and air cleaner), which are applicable to the category of KEPIC-MH (requirements for HVAC equivalent with ASME AG-1) when specified in the Design Specification.
KEPIC adopts KEPIC-MDP, MNC and MNG instead of ASME Section II Part D, Section III NC and NG; however, these are equivalent to each of the corresponding requirements.
Table 33—Composition of KEPIC-MNB 1000 and ASME NB 1000
KEPIC-MNB ASME NB Title Remarks
MNB 1110 NB-1110 ASPECTS OF CONSTRUCTION
COVERED BY THESE RULES KEPIC includes KEPIC-MI for ISI and KEPIC-MH for HVAC.
MNB 1120 NB-1120 TEMPERATURE LIMITS KEPIC adopts KEPIC-MDP instead of ASME Sec. II Part D.
MNB 1130 NB-1130 BOUNDARIES OF
JURISDICTION Same as ASME
(MNB 1131) (NB-1131) Boundary of Components Same as ASME (MNB 1132) (NB-1132) Boundary between Components
and Attachments KEPIC adopts KEPIC-MNC and MNG instead of ASME Sec. III NC and NG.
MNB 1140 NB-1140 ELECTRICAL AND
MECHANICAL PENETRATION ASSEMBLIES
Same as ASME
6.4 Materials Highlights
• KEPIC has adopted the calibration procedure of KRISS for a Charpy-V Impact Test Machine and the procedure has a narrower range of tolerance values and is more conservative than the requirements of ASTM E23.
• For NDE personnel, KEPIC additionally requires a national license based on Korean domestic law in addition to the requirements of ASME Section V.
ASME requires the calibration of the Charpy-V Impact Test Machine to follow ASTM E23-02a and use the standard specimen of NIST. However, KEPIC requires following KASTO 93-21102-094 (which is equivalent with ASTM E23-93) to reflect the reality in Korea, and uses the standard specimen of KRISS (Korea Research Institute of Standards and Science) in accordance with domestic laws. For reference, KASTO is the Korea Association of Standards & Testing Organization based on Korean laws and KRISS buys standard specimens from NIST. The calibration procedures of KRISS were developed under the ISO quality assurance system based on ASTM E23. However, it has a narrower range of tolerance values and is more conservative than the requirements of ASTM E23.
As for the nondestructive examination (NDE) requirements, it adopted KEPIC-MEN, technically the same as ASME Section V. However, as for NDE personnel, KEPIC additionally requires a national license based on Korean domestic law in addition to the requirements of ASME Section V.
KEPIC’s code symbol system is different from that of ASME and detailed matters are described in the comparison items of the administrative requirements in Clause 5.6 (the contents should be put in examination).
6.5 Design Highlights
• Design methodologies of KEPIC-MNB are the same as those for ASME Section III NB.
There is no difference between KEPIC and ASME regarding design.
6.6 Piping, Valves, and Pumps Highlights
• The requirements for piping, valves, and pumps of KEPIC-MNB are the same as those of ASME Section III NB.
The composition and requirements of KEPIC-MNB are essentially the same as those of ASME NB, as it adopted the same composition. There are no differences except those mentioned in the previous clause. Table 34 sums up the code layout comparison.
Table 34—Composition of KEPIC-MNB and ASME NB
KEPIC-MNB Contents ASME NB
MNB 3400 Pump Design NB-3400
MNB 3500 Valve Design NB-3500
MNB 3600 Piping Design NB-3600
6.7 Fabrication – Welding Highlights
• Fabrication requirements of KEPIC-MNB are the same as ASME Section III NB.
• KEPIC and ASME require t min. for the counterbore length of fittings for pre-service inspection (PSI), but KEPIC allows 0.5-inch counterbore length for fittings in Code Case.
There is no significant difference between KEPIC and ASME regarding fabrication. For reference, ASME requires t min. for the counterbore length of fittings for PSI, which is an additional requirement to acquire more NDE signals during the test conducted during the operation added after ASME BPVC 1995. This does not affect matters related to safety. Before then, the counterbore length of fittings was not separately specified even in ASME BPVC.
In any event, the related requirements of KEPIC are the same as ASME. However, in 2009 (comparing only up to 2007 Edition), the counterbore length of fittings of 0.5 inch was enabled with the Code Case, which shall be applied through an agreement with the regulatory organization. Korea has been building existing power plants by applying 0.5 inch, and has proven that it has not affected safety based on continued construction and operation of the power plants.
6.8 Examination Highlights
• NDE personnel qualification is different as they follow different requirements.
Regarding the PSI, KEPIC-MNA does not adopt the fracture mechanics data required by ASME NCA3252 (a) (6).
Regarding the certification of NDE personnel, ASME requires following ASNT SNT-TC-1A within the requirements of NB. However, as ASNT SNT-TC-1A is adopted in KEPIC-MEN, the NDE requirements, KEPIC-MNB, must follow KEPIC-MEN.
6.9 Pressure Tests
There is no difference between KEPIC and ASME with regard to the tests.
6.10 Overpressure Protection Highlights
• Personnel qualification follows KEPIC-QAR.
The terminology “NV Certification Holder,” which is used in ASME requirements, is expressed as
“Pressure Relief Valve Manufacturer” in KEPIC, operating a different code symbol system from ASME.
ASME requires following Section III Appendix XXIII for Personnel Qualification with regard to the Certification of the Overpressure Protection Report. However, KEPIC requires following KEPIC’s equivalent KEPIC-QAR. KEPIC-QAR has the same basic contents as Section III Appendix XXIII.
However, in terms of matters regarding national certification, the Korean national education system and qualification system are applied as shown in Table 35.
Table 35—Comparison Between KEPIC-QAR and ASME Section III Div. 1 Appendix XXIII
Description KEPIC ASME
Applicable Standard KEPIC-QAR ASME Sec. III Div.1 App. XXIII
Technical Field Identical to ASME Mechanical, Structural Required
National Certificate – Professional Engineer (2-yr job experiences), or – Engineer
(7-yr job experiences)
Registered Professional Engineer
Knowledge Identical to ASME Code &Working Knowledge
Accreditation Body KEA Certificate Holder
6.11 Overview of Quality Aspects Highlights
• KEPIC adopts KEPIC-MNA and KEPIC-QAP, while ASME has Subsection NCA and NQA.
As shown in Table 36, KEPIC develops and adopts KEPIC-MNA and QAP based on ASME BPVC Section III NCA and NQA-1, and integrates the requirements of ASME Section III Div. 3 WA as MNA. Regarding the Authorized Inspection, KEPIC-QAI, which was developed based on ASME QAI-1, and the “NB Rules and Regulations” of U.S. NBBI, were applied.
First, comparing KEPIC-MNA and ASME Subsection NCA, it can be said that KEPIC-MNA basically includes the contents of ASME Section III NCA and Div. 3 WA with the same basic
composition as that of ASME. However, as shown in
Table 38, it newly established KEPIC-MNA 6000 and has been operating various report forms, different from ASME NCA. In addition, the requirements related with Div. 2 among NCA requirements are separated as KEPIC-SNA, the general requirements of the structure part.
The code symbol system of KEPIC is based on the ASME system. However, as shown in Table 39, it is operated differently from ASME. The symbols are formally marked, rather than the use of code symbol stamping.
The differences of terminology between KEPIC-MNA and ASME NCA are shown in Table 40.
Second, comparing the KEPIC-QAP and ASME NQA-1, the KEPIC-QAP was based on the ASME NQA-1 1994 edition and 1995 Addendum, comprising QAP-1 and QAP-2 by maintaining the same structure (NQA-1, NQA-2) before the integration of ASME NQA-1 and NQA-2 (1994). All the requirements are the same as NQA-1, except matters that are applied with Korean domestic laws in terms of requirements.
Table 36—Comparison for QA and Administrative Requirements
Code Mechanical Concrete
Containment TC/SC Containment
ASME Sec. III General Requirement NCA NCA WA
Data Report Div. 1 App. Div. 1 App. WA
KEPIC
MN, SN General Requirement MNA SNA MNA
Data Report MNZ SNA MNZ
Table 37—Comparison for QA and Administrative Requirements
Description ASME KEPIC
Applicable Standard ASME QAI-1 KEPIC-QAI Organizations – Enforcement Authority
– Insurance Company Independent Organization to Owner,
Certificate Holder, and Material Organization
Accreditation Body ASME KEA
Government
Acceptance State Government
Enforcement Accepted by Regulatory Body if required
Table 38—Composition of KEPIC-MNB and ASME NB
Article KEPIC-MNA/SNA ASME Section III Subsection NCA
1000 General
2000 Classification of Components 3000 Responsibilities and Duties 4000 Quality Assurance
5000 Authorized Inspection 6000 Documentation (KEPIC only)
8000 Certificate, Nameplates and Code Symbol 9000 Glossary
Table 39—Comparison of Code Symbol System Between KEPIC and ASME Description ASME SectionIII Div.1 KEPIC-MN Components
1 1N
Parts & Appurtenance
3 3NP
Installation
2 2NC
Table 40—Terminology Comparison Between KEPIC-MNA and ASME NCA
Code Subsection ASME Section III
Subsection NCA KEPIC-MNA
Applicable
Organization Owner
N-Certificate Holder NPT-Certificate Holder NA-Certificate Holder Material Organization Pressure Relief Device Testing Laboratory
Owner Manufacturer
Manufacturer (only for Fabrication) Installer
Material Organization Pressure Relief Device Testing Laboratory
Accreditation Body ASME KEA
Table 41—Comparison Between KEPIC-QAP and ASME NQA-1
KEPIC-QAP ASME NQA-1 Title Remark
QAP-1 Part I Requirements of Nuclear
Quality Assurance Program for Nuclear Facility
Basic Requirements and Applicable Supplementary Requirements are mandatory to be adopted in KEPIC-XNA 4200
QAP-2 Part II & subpart 3.2
of Part III Quality Assurance Requirements for Nuclear Facility Application
Not adopted in KEPIC-XNA such as MNA, SNA etc., but applied in Contract Requirements
6.12 Conclusion
So far, KEPIC-MNB, the requirements for Class 1 pressure vessels, pumps, pipes, etc., has followed the spirit of ASME safety in terms of technical matters, and there are no technical differences.
In addition, in terms of QA and the administrative requirements related to nuclear safety, KEPIC-MNB adopted and has operated the requirements of ASME in most of the parts. However, it reflected the differences resulting from different laws and regulations and education systems in Korea from those of the U.S. KEPIC introduced ASME’s code symbol system and operates independent code symbol systems through simplification. However, there are no requirements to have been relaxed from ASME levels regarding safety.
Thus far, the differences between KEPIC and ASME BPVC with regard to Class 1 component-related requirements have been analyzed. In addition, the differences in QA and administrative requirements have been noted. As explained above, KEPIC-MN has the same technical matters, as it adopted the same contents of the technical requirements of ASME BPVC NB by adopting them unchanged.
In terms of the systematic parts, both have the same basic contents. However, KEPIC tried to be more subjective relating to the regulations with regard to regulations on nuclear power safety, system operation, qualification entitlement, etc., by naturally applying Korean domestic laws, albeit through the same basic frameworks.
In conclusion, KEPIC and ASME have no noticeable differences as regards nuclear safety. Class 1 components designed and manufactured in accordance with KEPIC-MNB can be applied in the power plant construction projects that are applied with ASME BPVC Section III.
KEA aims to establish various cooperative relationships with ASME, such as endorsing both parties of certificate holders under KEPIC or ASME.
7 CSA VERSUS ASME BPVC SECTION III COMPARISON