ML18018B655

Forwards Addl Info Re Equipment Qualification Program,Per 840321 Request.Summary of Radiation Considerations for Equipment Qualification in Mild/Harsh Environs Also Encl

ML18018B655
Person / Time
Site:	Harris
Issue date:	05/29/1984
From:	Zimmerman S CAROLINA POWER & LIGHT CO.
To:	Harold Denton Office of Nuclear Reactor Regulation
References
NLS-84-201, NUDOCS 8406040066
Download: ML18018B655 (16)

Text

SYEGULATORY INFORMATION DISTRIBUTION BY~TEN (RIBS)

'ACCESSION NBR:8406040066 DOC ~ DATE: 84/05/29 NOTARIZED: NO

,FACIL:50-000 Shearon Harris Nuclear Power PlantF Unit 1~ Carolina 05000400 AUTH ~ NAME, . AUTHOR AFF ILIATION ZIMMERMAN~S,R, Carolina Power & Light Co ~

NOTES'OCKET RECIP ~ NAME RECIPIENT AFFILIATION DENTONaH ~ RE Office of Nuclear Reactor Regulationr Director

SUBJECT:

Forwards addi info re equipment qualification programiper 840321 requests Summary of radiation considerations for=,

equipment qualification in mild/harsh environs also CODE: A048S COPIES RECEIVED:LTR J "ENCL - SIZE; encl'ISTRIBUTION TITLE: OR/L'icensing Submittal: Equipment Qualification RECIPIENT COPIES REC IP IENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL NRR LB3 BC 12 1 0 BUCKLEYtB 01 1 1 INTERNALB ELD/HDS1 12 1 1 GC 13 1 IE FILE 09 1 1 NRR KARSCHrR 1 1 NRR/DE/EQB ,07 2 2 NRR/DL DIR 14 1 1 NR ORAB 06 1 1 NRR/DS I/AE8 1 1 F 00 1 1 RGN2 1 1=

EXTERNAL; ACRS 15 8 8 LPDR 03 1 1 NRC PDR 02 1 NSIC 05 1 1 NTIS 31 1 1 TOTAL NUMBER OF COPIES REQUIRED: LTTR 25 ENCL 2<I

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CMK Carolina Power 8 Light Company SERIAL: NLS-84-201 MAY 39 1984

.Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation United States Nuclear Regulatory Commission Washington, DC 20555 SHEARON HARRIS NUCLEAR POWER PLANT, UNIT NO. 1 DOCKET NO. 50-400 EQUIPMENT QUALIFICATION

Dear Mr. Denton:

Carolina Power & Light Company (CP&L) hereby submits one (l) original and forty (40) copies of additional information on the equipment qualification program for the Shearon Harris Nuclear Power Plant. This information is submitted in response to the equipment qualification issues discussed at the meeting held on March 21, 1984 between the Nuclear Regulatory Commission Staff and CP&L.

e Should you,have any questions with regard to this issue, please contact Mr. Pedro Salas at (919) 836-8015.

Yours very truly, S ~ mmerman Manager Nuclear Licensing Section PS/lcv (9957PSA)

Attachments: I) Additional Information II) Radiation Considerations for Equipment Qualification in Mild/Harsh Environments Mr. Goutam Bagchi (NRC-NRR/EQ) Mr. G. F. Maxwell (NRC-SHNPP)

Hr. B. C. Buckley (NRC-NRR/LB) Mr. J. P. O'Reilly (NRC-RII)

Hr. G. O. Bright (ASLB) Mr. Travis Payne (KUDZU)

Dr. J. H. Carpenter (ASLB) Mr. Daniel F. Read (CHANGE/ELP)

Hr. Wells Eddleman Mr. John D. Runkle Mr. J. L. Kelley (ASLB) Mr. J. N. Singh (EG&G)

Mr. Clarke Kido (EG&G) Dr. Richard D. Wilson Hr. Bob Legrange (NRC-NRR/EQ) Wake County Public Library Dr. Phyllis Lotchin Chapel Hill Public Library Hr. Armand Masciantonio (NRC-NRR/EQ) 411 Fayettevilte Street o P. O. Box 1551 ~ Raleigh, N. C. 27602 pa<

8406040066 840529 PDR ADOCK 05000400 A PDR

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ATTACHMENT I SHEARON HARRIS NUCLEAR POWER PLANT EQUIPMENT QUALIFICATION PROGRAM ADDITIONAL INFORMATION I. Valves Included in the Pum . and Valve 0 erabilit Review Issue: The Nuclear Regulatory Commission (NRC) Staff has requested that valves two inches and under be included in the pump and valve operability review.

Response: Carolina Power & Light Company (CP&L) will include valves two inches and under in the pump and valve operability review.

II. Documentation of E ui ment Reviewed Under the Mechanical E ui ment alification Pro ram Issue: The NRC Staff has requested that packages be prepared for all equipment reviewed under the mechanical equipment qualification program.

Response: Consistent with the preparation of packages for the Catawba audits, Carolina Power & Light Company will prepare packages for the equipment that the NRC selects for the audit. Carolina Power & Light Company feels packages are not necessary for all equipment since all documentation generated by this effort will be kept readily retrievable and available for audit. Quality Assurance (QA) records will be maintained in the QA vault on-site. Drawings used will be available from the document control system on-site. The system used to generate data on particular components or types of materials (e.g., activation energies, thermal degradation curves, etc.) will be maintained at the Architect/Engineer's (Ebasco) office through December, 1984 when the effort will be concluded and at the CP&L offices following that date.

III. Definition of Harsh Environment Issue: The NRC Staff has requested that an environment be considered harsh if the total integrated dose (TID) encompassing forty years installation during normal'plant operation and one year post-accident 4

installation, is greater than 10 rads.

Response: Carolina Power & Light Company's position on TID threshold for the definition of harsh environment is presented in Attachment II.

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IV. Acce tance of Vendor Su lied Re orts Issue: The NRC Staff has requested a description of CP&L's review and approval of vendor supplied reports.

Response: Carolina Power & Light Company has contracted its Architect Engineer (Ebasco) and its Nuclear Steam Supply System vendor (Westinghouse) to review, on its behalf, the reports supplied to them.

CP&L has reviewed and accepted the Ebasco and Westinghouse gA programs and has reviewed and accepted selected vendor supplied reports.

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ATTACHMENT II SHEARON HARRIS NUCLEAR POWER PLANT RADIATION CONSIDERATIONS FOR E UIPMENT QUALIFICATION IN MILD/HARSH ENVIRONMENTS CONTENTS Introduction Definition of Mild Environment Selection of Equipment Covered by 10 CFR 50.49 Determination of a "Radiation-Harsh" Environment Conservatism in the Radiation Environmental Conditions Conservatism of the Harris EQ Program II-1 (9957PSA/cf r)

I. Introduction On March 21, 1984, representatives of the Shearon Harris Nuclear Power Plant (SHNPP) Equipment Qualification Team met with representatives of the Nuclear Regulatory Commission (NRC) Equipment Qualification Branch.

The purpose of the meeting was to present and discuss Carolina Power &

Light Company's (CP&L's) Equipment Qualification Program for Shearon Harris Unit 1. During this. discussion, the NRC requested clarification on our methodology for determining and defining "mild environment" with respect to radiation dose. This report has been prepared to address CP&L's approach to this matter for SHNPP.

CP&L has used Section B, Regulatory Guide 1.89 (Revision 1, Draft) as a basis for equipment qualification radiation considerations. It reads as follows:

"The following are examples of considerations to be taken into account when determining the environment for which the equipment is to be qualified: (1) equipment outside containment would generally see a less severe environment than equipment inside containment; (2) equipment whose location is shielded from a radiation source would generally receive a smaller radiation dose than equipment at the same distance from the source, but exposed to its direct radiation; Electrical equipment to be qualified in a nuclear radiation environment should be exposed to radiation that simulates the conservatively calculated integrated dose (normal and accident) that the equipment should withstand prior to completion of its intended safety function."

CP&L's rigorous approach to radiation qualification, based on case-by-case qualification tests and analysis supported by tests or previous qualification information, assures the adequacy of equipment. This approach assesses the severity of radiation environments at locations where other environmental parameters are clearly mild. The same approach is applied 'to threshold values for solid state components. The methodology complies with NUREG-0588, including specific consideration of radiation effects in all plant areas, and does not generally exclude from consideration equipment exposed to a low radiation dose (i.e., below the sometimes considered negligible).

CP&L's approach to harsh environment radiation test consideration for SHNPP is consistent with an NRC staff response to public comments(*) on Proposed Regulatory Guide 1.89, Revision 1 wherein it was stated,

. The present position permits exemption of materials and equipment

Reference:

"Analysis of Public Comments" (response to Comment Nos. 74-83),

enclosure to Draft Revision 1 of Regulatory Guide 1.89, transmitted to J. C. Saldarini, Ebasco Services Incorporated, by USNRC letter dated November 14, 1983, from S. K. Aggarwal, EE Branch, Division of Engineering Technology, Office of Nuclear Regulatory Research.

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from qualification testing at any (dose) level if previous operating experience or previous qualification information can be provided which shows operability of the materials or equipment for the planned radiation environment."

Based on the conservatism applied in the derivation of the specified radiation parameters, a conservative program for selecting qualification methods and implementing these methods in the overall environmental qualification program as discussed herein, it is concluded that the SHNPP qualification methods established with respect to radiation considerations in environments considered to be mild provide an acceptable method for complying with NRC regulations with regard to accommodating the effects of environmental conditions.

II. Definition of Mild Environment The recent environmental qualification rule, 10 CFR 50.49 (hereafter called the EQ Rule), defines a mild environment as follows:

. an environment that would at no time be "si nificantl more severe" than the environment that would occur during normal power plant operation, including anticipated operational occurrences."

The definition does not require blanket exclusion from mild environment consideration all accident conditions that numerically exceed non-accident conditions. Rather it allows for considerations based on how and under what conditions the definition is applied.

CP&L has reviewed the available guidance pertaining to application of this definition, including material prepared before and after issuance of the EQ Rule (e.g., NRC presentations and workshops, IEEE and EPRI-NSAC documents). CP&L representatives have attended several recent seminars (e.g., EPRI-NSAC 1983 Seminars) and presentations (NRC/ACRS meeting December 1, 1983) where application of this definition was discussed.

CP&L has also reviewed in detail the latest available draft (November 9, 1983) of Regulatory Guide (RG) 1.89, Revision 1, and NRC's in-depth analysis of public comment, dated November 4, 1983, on proposed RG 1.89, Revision 1, containing a compilation of public comments and NRC staff responses.

Based upon this guidance, CP&L interprets the term "si nificantl more severe" (as incorporated in the NRC definition above) as follows:

"A mild environment may exceed the normal expected environment but does not expose the equipment to sudden or prolonged high-stress conditions during or following design basis events."

This clarification focuses on the intention of the SHNPP "harsh" environment qualification effort to review and evaluate the potential for equipment common-mode failures due to high stress from the environment, in accordance with'he prescribed methods required by the EQ Rule. This effort is preceded by a review of equipment locations and design capabilities to determine which equipment may be stressed in this manner.

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It is important to consider that since the EQ Rule, and even its precedent NUREG-0588, were issued during an advanced stage of the SHNPP program, environmental qualification including consideration of equipment aging was ongoing, or completed, for safety-related equipment in accordance with the General Design Criteria and RG 1.89, Revision 0.

This was documented originally in the PSAR, and subsequently in the FSAR, including reference to the industry standards being utilized.

The major impact of later NRC directives on environmental qualification has been on the extent to which documentation is submitted and/or made available to the NRC Equipment Qualification Branch for review and site audit. CP&L has been aware of the need for radiation qualification either by test or analysis and has included it in the SHNPP program dating as far back as issuance of IEEE 323-1971. Therefore, the SHNPP specifications and qualification plans included this requirement.

The initial task, then, in applying the EQ Rule to SHNPP, was to determine which equipment in the existing program was included under the scope of this rule.

III. Selection of E ui ment Covered b 10 CFR 50.49 The equipment selection process covers both equipment functions and equipment environments. Therefore, review and analysis other than those concerning environmental stress severity are clearly necessary to determine which equipment is covered by the EQ Rule. These tasks encompass most plant equipment in some manner and are subject to the quality assurance program requirements per 10 CFR 50, Appendix B. For example, some of the review processes involved are as follows:

A. E ui ment function durin desi n basis events safety system functions and the components which are relied on to remain functional are identified and segregated from those systems and components which do not have a safety application.

B. Nonsafet -related e ui ment this equipment is reviewed to determine if its failure under environmental conditions could prevent the accomplishment of safety functions.

C. Post-accident monitorin e ui ment this equipment is reviewed per the guidance in RG 1.97.

D. Establishment of environmental conditions the environmental conditions for safety-related equipment are determined for various plant operating conditions and design basis events.

E. Review of the severit of accident conditions the severity of the environmental conditions during/after the applicable postulated accident are assessed for safety-related equipment.

It should be noted that specific qualification information (i.e.,

documentation) is explicitly within the scope of the EQ Rule only for the equipment covered by the rule (refer to 10 CFR 50.49(d)). Therefore, II-4 (9957PSA/cfr)

with respect to environmental stress severity (i.e., significance of a change in equipment environmental conditions), it is CP&L's understanding that information supporting the case-by-case equipment assessment is one aspect of that specific qualification documentation.

k However, in conjunction with this assessment, CP&L recognizes an implicit concern in the EQ Rule regarding the methodology for determining the significance of environmental conditions for safety-related equipment.

As this methodology directly affects the scope of the rule, review by the Equipment Qualification Branch is warranted. In fact, the SHNPP project has allotted specific resources and schedule to the special "harsh" environmental qualification effort based on its understanding of the scope of the harsh environment environmental qualification review aqd audit. CP&L's 10 CFR 50.49 scope definition for SHNPP was carefully considered addressing the available guidance prior to the March 21, 1984 presentation given to NRC. Furthermore, CP&L is pursuing environmental qualification per the FSAR, regardless of whether favorable conditions are expected at the equipment location.

IV. Determination of "Radiation-Harsh" Environment With regard to the discussion at the March 21, 1984 meeting concerning the significance of radiation dose, the following considerations are applied for equipment at a location where other environmental conditions are clearly "mild":

A. It is noted that the SHNPP safety-related equipment design/purchase specifications have conservatively specified a total integrated dose (TID), encompassing forty years installation during normal plant operation and one year post-accident installation, as opposed to segregating a normal dose versus accident dose. Therefore it is appropriate to assess the equipment design capability based on TID, considering the available test data or analysis supported by tests.

This conservative approach provides assurance that components sensitive to low level doses are not excluded from radiation qualification testing. An alternative approach, such as assessing a harsh environment based on the percentage dose increase due to an accident, may not provide the same assurance at a location where the calculated normal dose is above a component's threshold dose.

Therefore, by specifying the TID, radiation conditions can essentially be considered as normal conditions (where other conditions are mild and within certain limits, as described in Item 2, below) ~

B. If the TID at the equipment locat)on, which includes gamma and beta contributions, is greater than 10 rads the environment is considered harsh (i.e., equipment qualification is covered by 10 CFR 50.49),

except under the following conditions:

l. Equipment lo~ations exposed to a TID greater than 10 3 rads but less than 10 rads, which exclude critical semiconductor components and organic materials potentially sensitive in this II-5 (9957PSA/cfr)

range(*). Critical components or materials are those which are essential for performance of a safety function.

2. Equipment locations exposed to a TID greater than 10 3 rads but less than 10 rads, which include critical semiconductor components and potentially sensitive organic materials may be excluded based on qualification tests or analysis supported by tests indicating that the TID can be absorbed without serious degradation (i.e., the TID is well below the material capabilities) so that it does not place in substantial doubt the ability of the components to function.

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3. Shielded equipment locations may be excluded considering the appropriate shielding factors, provided the sum of the gamma and re)uced beta dose is (1) )0 rads, maximum, of (ii) greater than 10 rads but less than 10 rads and the equipment location satisfies condition B,l or B,2, above.

CP&L recognizes that the EQ Rule does not list specific values of environmental parameters, in part due to variations in equipment selection/qualificaton processes employed at specific plants, which includes different vintage plants. Therefore, CP6L has specified the above considerations in the qualification process for the Harris Plant.

The SHNPP methodology for addressing radiation conditions is more conservative than the position indicated by the industry and submitted to NRC by the Atomic Industrial Forum(**), which argues for exemption from radiation qualification based on threshold values, no matter how the equipment is applied or under what conditions.

The industry position is as follows:

"That equipment located in areas where total integrated gamma dose levels over the life of the plant or equipment including the post-accident doses do not exceed 10 5 rads (conservatively estimated to be one order of magnitude less than the threshold of detectable effects) should be exempt from requirements to demonstrate its radiation aging capabilities by type testing and/or analysis.

solid state electronic devices, the threshold level should be 10F~r rads gamma."

• EPRI Report NP 2129, dated November 1981, Radiation Effects on Organic materials in Nuclear Plants, provides a basis for assessing the sensitivity of materials listed in its Table 4-1, to doses in this range.

• • Atomic Industrial Forum letter from R. M. Eckert to R. H. Vollmer, USNRC, dated August 24, 1982, transmitting a Nuclear Industry Position Paper on Radiation Considerations for Equipment Qualification.

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V. Conservatism in the Radiation Environmental .Conditions Dose values for 40 years normal operation were derived primarily. from previously established dose rates developed for plant shielding and personnel protection purposes (see Section 12.3 of the PSAR). Radiation source and equipment locations, shielding configurations, system and equipment operations were considered. Maximum dose values (based on assumptions of nuclide activities in the reactor coolant corresponding to 1.0 percent failed fuel, extreme of operation, etc.) rather than the average or expected dose rates (allowed in the introduction of Position 1.4 of NUREG-0588) are used. Thus, the calculated normal operations doses are conservatively high The DBA radiation exposure is predicted on assumed instantaneous release fractions of different classes of radionuclides from the core following the incipience of the accident. These assumptions are stated in NUREG-0588 and elsewhere (such as TMI document NUREG-0578 and NUREG-0737, and Regulatory Guide 1.4). Both beta 'and gamma doses to equipment were considered in arriving at a total dose for qualification purposes, including a one year post-DBA period following 40 years normal operations. Time-dependent radionuclide transport phenomena, such as plateout and washout (removal from the containment atmosphere by containment spray), were factored into the source term development, and hence, the dose calculations. Details of the methods and assumptions will be provided in the SHNPP environmental qualification submittal.

The assumption in NUREG-0588 of instantaneous release of radionuclides from the core coincident with the start of an accident is extremely conservative. There is ample evidence based on NRC and industry sponsored research (e.g., WASH-1400) to demonstrate substantial conservatism in the NRC assumption as follows:

C. The core cannot begin to melt, and thus release the bulk of its contained radionuclide inventory, for a time period on the order of 10 minutes, under the worst case accident scenario.

D. Even as the core meltdown begins all radionuclides would not be released at once but rather would be released over some extended period of time.

E. Different radionuclides would have different release rates. In addition, the chemical form of the fission products released from fuel is of equal importance to the percent that is released.

VI~ Conservatism of the Harris E Pro ram CP&L believes that the provisions of the EQ Rule allow for the considerations presented herein. The overall SHNPP environmental qualification program (harsh and mild environments) is a conservative one. If CP&L determines that an environment is harsh due to radiation dose alone, CP&L has strived to obtain a type test that includes preaging and operability under multiple environmental parameters,'ince criteria to address things such as combined environments are not well established. The NRC staff concurred with the conservatism of this II-7 (9957PSA/cfr)

approach at the March 21, 1984 meeting. Finally, under the SHNPP environmental qualification program no electrical equipment is automatically considered exempt from radiation testing, even that equipment which may be exposed to doses below those considered mild.

In addition, CP&L has often purchased equipment on a lot basis and qualified it for the worst case environment (i.e., in-containment design basis accident (DBA) environment, maximum duration, maximum performance ratings) regardless of various individual locations, to minimize the number of different plant components. Therefore many components located in environments considered mild are qualified for more severe conditions.

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