ML20202C114
| ML20202C114 | |
| Person / Time | |
|---|---|
| Site: | Portsmouth Gaseous Diffusion Plant, Paducah Gaseous Diffusion Plant |
| Issue date: | 01/30/1998 |
| From: | Toelle S UNITED STATES ENRICHMENT CORP. (USEC) |
| To: | NRC OFFICE OF ADMINISTRATION (ADM) |
| References | |
| TASK-*****, TASK-RE GDP-98-0014, GDP-98-14, NUDOCS 9802120167 | |
| Download: ML20202C114 (9) | |
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A cio61 ea.rry compaar January 30,1998 Rules and Directiws Branch. DAS SERIAL: GDP 98-0014 Office of Administration U. S. Nuclear Regulatory Commission Washington. DC 20555-0001 Paducah Gaseous Diffusion Plant (PGDP)
Portsmouth Gaseous Diffusion Plant (PORTS)
Decket Nos. 70-7001 and 70 7002 Comments on Draft Regulatory Guide DG-1070 This letter provides the United States Enrichment Corporation (USEC) comments on Draft Regulatory Guide DG 1070, " Sampling Plans Used for Dedicating Simple Metallic Commercial Grade items for Use in Nuclear Power Plants. USEC's comments are provided in Enclosure 1.
If you have any questions regarding this submittal, please contact Mark Lombard at (301)564-3248. There are no new commitments contained in this submittal.
Sincerely,
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- s. A.
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5.even A. Toelle Nuclear Regulatory Assurance and Policy Manager
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NRC Region III NRC Resident inspector - PGDP NRC Resident inspector - PORTS NRC Special Projects Branch, NMSS.-
9802120167 900130
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PDR ADOCK 07007001 p
6903 Rockledge Drive. Bethesda. MD 20817 1818 Telephone 301-564-3200 Fax 301-564-3201 http://www.usec.com Offkes in Livermore. CA Paducah. KY Portsmouth. OH Washington, DC 1
GDP 98-0014 Page 1 of 8 Backcround Recently, the Nuclear Regulatory Commission (NRC) has indicated a concern with sampling in the commercial grade item dedication process. The NRC has issued Draft Regulatory Guide (DG-1070)," Sampling Plans for Dedicating Simple, Metallic Commercial Grade Items at Nuclear Power Plants" to provide additiona' guidance in this area.
Since the United States Enrichment Corporation (USEC) utilizes some of the industry guidance that has been developed by nuclear utilities, USEC is ver, interested in the promulgation
'any NRC regult
.i that could impact that industry guidance. USEC also paricipates in several nuclear industry organizations. One of these organizations, namely the Nuclear Energy Institute (NEI), has coordinated a review of DG-1070 and has compiled comments from several sources. This enclosure, developed from the industry comments compiled by NEl, seeks to explain why the USEC and representatives from various nuclear utilities believe additional NRC guidance is not needed to ensure that quality spare parts and equipment continues to be installed in operatir nuclear plants.
Scone of Draft Reculatory Guide The Drafl Regulatory Guide states that it applies only to simple metallic items. It is assumed l
that this Drall Regulatory Guide would be the regulatory position for all dedicated items and notjust simple metallic items. It is also assunad that if an inspector is reviewing a supplier or licensee 6dication plan for any item, the sampling size would be reviewed. In the absence of any other ahernative, the inspector would likely detault to the Regulatory Guide for acceptable sampling
. practices (this could also be the case for certificate holders like USS The Draft Regulatory Guide also states that it applies only to items intended for high safety significant plant applications, or where the plant application is not known. This would require that licensees would almost always be defaulting to the NRC recommended p'an (95/5) for the following reasons:
1.
Most licensees have not performed a safety / risk analysis down to the component level and do not intend to because of the required investment. The Draft Regulatmy Guide implies that unless the safety significance has been determined, it must be assumed to be high and the 95/5 confidence level must be used.
2.
Most licensees procure and stock items for general plant use. These items are dedicated based on the most restrictive or severe plant application. The Draft Regulatory Guide implies that either separate stock numbers must be generated for separate applications, on the NRC recommended sampling sizes must be used.
3.
Suppliers are typically not aware of the safety significance of the plant application they are supplying the dedicated item for.
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GDP 98-0014 Page 2 of 8 Based on the fact that the Drafl Regulatory Guide may notjust be applied to simple metallic parts, and assuming that it applies to those items which are of high safety significance and/or have not had their safety significance determined, this Drall Regulatory Guide would apply to almost all licensee and supplier dedications.
Performance llistory of Dedicated Commercial Grade Items Since licensees and 10 CFR 50, Appendix B suppliers first implemented enhanced dedication programs in the mid to late 1980s, they have utilized sampling pt as when accepting commercial grade items. Based or the following considerations, performance of these items has b:en adequate to ensure safe plant operation:
Safety and non-safety related equipment procured and installed in operating units continues to demonstrate a high degree of reliability There is a lack of inservice failures of safety related parts and components related to dedication Plant reliability continues to increase even as the number of Appendix B suppliers is
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shrinking and the amount of dedication is increasing.
There is a lack of adverse trends in the quality of material procured as shown by utility QC tests and inspection results.
No appreciable failure rates for the amplified testing (overchecks) of fasteners performed during the late 1980s and early 1990s exists.
As the NRC states in the int od.ction of their Technical Report on sampling issued last February, "Through the years, NPP experience has shown that, in general, most plant equipment can be counted on to operate reliably and safely. This observation is also true concerning the parts used to repair or replace that equipment."
To support the licensee perception that dedicated items are performing well in service, a survey was issued to gather data. Nuclear utilities were asked to provide the number ofitems that they have dedicated since January 1994 and the number of falhtres that were identified related to the dedication process. The following table summarizes the data submitted:
GDP 98-0014 Page 3 of 8 Utility WiUnits Number of items Dedicated Number ofitems That linve Failed A
3 3.645 stock numbers None 1.200 non-stock numbers B
4 3.118 P.O. line items None C
7 2.500 commercial erade parts Issued 27 (none were simple rhetallic pa.1s)
D 2
310.000 individual parts None E
4 133.924 None F
12 48.000 line items None G
I 4.000 line items None 11 4
3.107 P O. line items None 1
I 218 line items None J
2 1.000 line items None it I
l.207 lin,e items None L
8 1.700 individual components / parts l hone Because of the nature of the data supplied by the utilities, it is difficult to extrapolate an approximate number for the entire industry. One line item could equal 10,20 or 50 actual items, llowever, the results do indicate high performance and a lack of appreciable failures of dedicated items.
Regulatory Basis for Samnline Durine the Dedication Process To ensure that the current sampling programs are in accordance with regulatory requirements, various regulatory documents were investigated to extract any guidance related to sampling:
1.
10 CFR 50, Appendix B, Criterion VII states-Measures shall be established to assure that purchased material, equipment, and services, whether purchased directly or through contractors and subcontractors, conform to the procurement documents. These measurt.s shall include provisions, as appropriate, for source evaluation and selection, objective evidence of quality furnished by the contractor or subcontractor, inspection at th contractor source, and examination of nroducts unon deliverv...The effectiveness of the control of quality by contractors and subcontractors shall be reassessed by the applicant or designee at intervals consistent with the imnortance. comnlexity. and ouantity of the products,
services.
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GDP 98-0014 Page 4 of 8 2.
The introduction of10 CFR 50, Appendix B states:
... quality assurance comprises all those planned and systematic actions necessary to -
j provide adequate confidence that a structure, system, or component will perform f
satisfactorily in service?'
3.
ANSI N45.2.2 - 1977,- Paragraph 11 states:
Examinations, measurements. or tests ofitems processed shall be performed for each work operation where necessary to assure quality. Where a sample is used to _ verify acceptability of a group of items, the sampling procedure shall be based on recognized standard practices and shall provide adequate justification for the sample size and selection process.
3.
ANSI N45.2.13 - 1976, Section 7.3.2 (endorsed by Reg. Guide 1.123) states:
Sampling may be used during receipt inspection when conducted in a accordance with established procedures or recognized standards.
4.
. ANSI N45.2.2 - 1972, Section 5.2.2 (endorsed by Reg; Guide 1.38) states:
- Statistical sampling methods may be used for groups of similar items.
5.-
.10 CFR 21 defines commercial grade dedication to be:
... dedication h an acceptance process undertaken to provide reasonable assurance that a commercial grade item to be used as a basic component will perform its intended
-- safety function and, in this respect, is deemed equivalent to an item designed and manufactured under a 10 CFR 50,' Appendix B, quality assurance program.
Therefore, the procurement and dedication process i iust one of the elements of a plant's overall quality assurance program.
Cost of Regulatory Guide Imnlementation I
The cost to implement the guidance provided on the Draft Regulatory Guide.would be significant to the industry. The guide not only provides a tighter sampling size than most licensees and suppliers use on larger lots, but it provides recommended critical characteristics and acceptance -
criteria for simple metallic items. Increased costs would be caused by the following:
The man-hours required to complete additional testing will require adding personnel to staff.
The procurement of additional test equipment to accommodate increased testing.
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4 GDP 98-0014 Page 5 of 8 Increased number of stock numbers and total stock to accommodate different levels of safety significance.
The cost to revise current procurement engineering and dedication procedures to address revised sampling practices.
The cost to revise all current dedication plans.
The increased cost of items that were dedicated by approved 10 CFR 50, Appendix B suppliers who significantly increase sampling because they must assume items are intended for safety-significant applications.
' increased engineerir.g time to evaluate homogeneity oflot. There will also bc increased costs to obtain the level oflot nomogeneity the Regulatory Guide recommends before sampling.
Many of the tests the NRC considers nondestructive, would actually be destructive for small i
simple metallic items. Therefore, a significant number of additional products would need to be procured.
Increased off-site testing because many utilities and suppliers do not currently have all of the test equipinent required to complete testing specified in the Draft Regulatory Guide.
The time to coniplete dedication will be increased which may have an affect on parts availability to support plant operation.
The cost of obtaining additional paperwork from suppliers (such as, CMTRs, Certificates of Conformance, etc.)
The following hypothetical example was developed to illustrate the additional costs which would be incurred using the guidance provided in the Draft Regulatory Guide.
Item to procured: 1/2 x 20 bolts, ASTM A307 Grade A, carbon steel Number items to be procured: 100 Cost per item: $.08 Sssnario A: Current Utility Samn_ line Practices According to the Joint Utility Task Group (JUTG) Technical Evaluation CGIFA01, " Bolts, 1/4 Inch and Above", the following critical characteristics would be verified to provide reasonable assurance the bolts would perform their safety function:
Material composition Material strength (see Note 1)
Coating or plating material
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GDP 98 9014 l.
Page 6 of 8
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~ Configuration (hsx head, heavy hex, etc.)
- Pitch diameter or size 1
Threads per inch or pitch
.i Overalllength -
1 Head height Width across flats or head diameter i Thread length -
Note: Approprate test methods include tensi!e, load or hardness tests depending ipon specific size, geometry and material type. Tests should be conducted in accordance with appropriate industry standard test techniques, Hardness may be used
'in lieu of tensile or load testing for appro- m materials. ASTM A370 establishes a correlation between hardness values ar i " uimate tensile strengths for carbon and alloy steels. However, surface hards..aiations may be present due to heat
- treatment, machining or other working of the material < The applicability of the
- ASTM A370 correlation of hardness to desired mechanical properties should be
- reviewed as appropriate.
Based on an engineering review of factors including dedication history, lot formation type, complexity of the item, insenice performance history, engineering would develop a sample size.
For this example, the normal sample size out of EPRI Report NP-7218 is selected which results in a sample size of 18. It is assumed that using available test equipment, all dedication testing (including the hardness to verify material strer.gth) can be penbrmed without destroying the bolt.
Fo' r this example, it is assumed the fully burdened rate of receipt inspection / testing personnel is
$50.00 per hour. It would take approximately three hours for the items to be tested. Therefore the total cost for this procurement would be $158.00 (testing cost plus the cost of the material).
Scenario B: Draft Renulatory Guide Practices Based on a review of the Dran Regulatory Guide, the following additional characteristics / testing would be required:
- = - Full chemistry composition analysis within tolerances specified in Draft Regulatory Guide
. ($250)'
Full physical testing as specified in Draft Regulatory Guide including destructive testing ($250)
= Procurement of CMTR or other paperwork to develop lot homogeneity requirements (S250)
GDP 98-0014 Page 7 of 8 Review of paperwork against requirements in Draft Regulatory Guide (one additional man hour)
Preparation ofitem and paperwork to ship for off site testing and review of results upon receipt
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back at the warehouse (3 additional man hours) 1 The additional cost to the procurement utilizing the Draft Regulatory Guide is $950.16 which includes the cost of two bolts to destroy. The total cost increases from $150.00 to 1,150,16 which is a factor of 7.6.
hst andJ!roposed Actions to Resolve Perceived Sampline Issue in 1995, representatives from the Nuclear Utility Procurement Issues Committee (NUPIC)
Stecting Consnittee met with the NRC to discuss procurement, it was suggested that utility auditors need to be;ter document the review of sampling activities. As a result, the NUPlc checklist was revised and additional guidance has been provided to arditors.
The NUPlc checklist has been revised to provide additional guidance on ensuring that manufacturers have a technically justifiable sampling plan.
I The nuclear industry will sponsor several workshops to inform manufacturers and licensee procurement and audit personnel on what nuclear utilities consider to be a technically justifiable sampling plan. Infonnation developed for the workshop will be used to enhance the EPRI Nuclear Procurement Training Course Module on Sampling in the Dedication Process.
The Electric Power Research Institute has made EPRI Report NP-7218. " Utilization of Sampling Plans for CGI Acceptance", available to all licensees and suppliers who have requested a copy. The report is presented as one industry-recognized standard practice to consider. Licensee members have also directed EPRI to develop a revision to NP-7218 to address the following issues:
Sampling sizes for destructive testing Consideration of safety function and safety significance when selecting a sample size Lot homogeneity considerations The revision will be initiated in January 1998 and should be completed by June of the same year.
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GDP 98 0014 -
Page 8 of 8 Concinalen Based'on the excellent performance history of dedicated ' commercial grade Pems, USEC believes that the current' sampling programs utilized byilcensees and 10 CFR 50, Appendix B manufacturers / suppliers are adequate to ensure safe operation of nuclear plants. The licensees believe that the~ sampling plans utilized are in accordance with current regulatory requirements and.
industry standards, and that no additional guidance from tlie NRC is required.- -
i-USEC also believes that implementation 'of the recommendations _ provided in Draft -
Regulatory Guide DG 1070 would significantly increase the cost of procurement without improving the quality installed items.
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