Proposed Task Group: Electrical Cable and Condition Monitoring Codes and Standards for Nuclear Power Plants

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1 Proposed Task Group: Electrical Cable and Condition Monitoring Codes and Standards for Nuclear Power Plants Dr. Stephanie Watson Engineering Laboratory, NIST

2 Cables in NPPs Categories Medium voltage power (2.4 kv to 34 kv) Low voltage power ( 1 kv) Control Instrument Panel and hook up wire Specialty Security Telephone Lighting Grounding Distribution of circuit cables: 20% instrument; 61% control; 13% AC power; 1% DC power; 5% communication Medium voltage cable includes metallic shield (helically wound tapes, distributed drain wires, longitudinally corrugated copper, concentric neutral wires )

3 Cables in NPPs Additives: anti oxidants flame retardants fillers plasticizers Newer halogen free materials from IAEA

4 What is the problem? Safety and performance concerns about electric cables (low and medium voltage) in aging nuclear power plants Many cables are inaccessible or are a part of underground cable circuits Large number of cables at plants, need to identify those cables at greatest risk based on cable function and its environment (temperature, moisture, radiation, voltage) Lack of minimally invasive testing methods for medium voltage cables Unknown aging effects of newly developed insulation materials (zero halogen ) Many codes and standards currently used for new nuclear energy facilities are outdated 4 to 11 years since revisions; many rescinded. Lack of standards for: acceptance criteria for non destructive tests tests of unshielded cables

5 How is it solved today? Electrical Cable Performance from US NRC

6 What are the needs in test standards? Determination of remaining lifetime of currently aged cables Standardization of procedures for condition monitoring test methods Calibration of equipment and optimization of test parameters Optimization of acceptance criteria Determination of aging mechanisms for:» Low voltage cables under wet conditions» High voltage cables under temperature, radiation, and wet conditions» Newly developed insulation materials» Determination of the effectiveness of cable splicing and aging processes Standard sampling techniques for microsampling methods Acceptable to operators and regulators Training materials for NPP operators

7 Presentations at the March 2011 NESCC Meeting Nuclear Plant Cable Aging Management in the US with regards to Standards Gary Toman, EPRI Cable Performance Challenges in the Nuclear Industry Thomas Koshy, US NRC IEEE Nuclear Standards Qualification Process: Aging and Performance of Cables James Gleason, IEEE

8 Objectives for the Proposed TG Establish coordination and consistency of safety and non safety related electrical cable requirements Identify new design requirements for electrical cables New polymeric components Condition monitoring tests Develop a plan to incorporate new requirements into codes and standards Identify and review all U.S. NRC RG related to electrical cables.

9 Task Group Membership Representation from: Relevant SDOs IEEE, IEC, and ICEA Nuclear power plant industry NEI, EPRI, Engineering Design and Construction firms, and utilities NRC staff licensing and inspection Other experts in specific fields as needed

10 Proposed Path Forward Convene a Task group Members (all or subset) review the Mattson report, all NRCregulatory documents, and SDO (IEEE, IEC, ICEA, and UL) documents to identify all references to electrical cable codes and standards Categorize all endorsed electrical cable codes and standards as: upto date, outdated but appropriate for application, reference needs revision Identify electrical cable codes and standards that are currently lacking Identify research needs to support development of lacking codes and standards Draft report with recommendations submitted to members for review and comment Final report submitted to NESCC

11 Expected Outputs Inventory of relevant NRC standards with gaps and overlaps identified Recommendations for revision or new development of electrical cable standards Review of current citations of electrical cable codes and standards in NRC regulatory documents

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13 Task Group (TG) Structure Chair Communicate with NESCC board and task group Organize and conduct TG meetings and minutes Prepare list of relevant standards Submit recommendations to NESCC and NRC Review revised TG and/or member reports Members Review standards and give preliminary recommendations (sub TG could be formed by group of experts in specific areas) Vote on recommendations

14 Proposed Schedule July 2011 Form task group Review list of currently endorsed documents on electrical cables July 2012 (?) Draft a report on findings with recommendations Submit recommendations to NESCC

15 Procedure for Task Group Members (or a subset) review a document and provide recommendations Chair distribute to all members for comments and ballot Resolve opposition and comments Submit to NESCC