Text

Informs Commission of Staff Intent to Issue Proposed NRC GL 99-XX, Lab Testing of Nuclear-Grade Activated Charcoal
	ML20207C817
Person / Time
Issue date:	05/14/1999
From:	Travers W; NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO)
To:	;
References
	SECY-99-132, SECY-99-132-01, SECY-99-132-1, SECY-99-132-R, NUDOCS 9906030117
	Download: ML20207C817 (49)
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POLICY ISSUE

. L May 14.1999 (InfOrmation)

SECY-99-132

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FOR:

The Commissioners l

i FROM:

William D. Travers y

Executive Director for Operations

SUBJECT:

PROPOSED NRC GENERIC LETTER 99-XX, " LABORATORY TESTING OF NUCLEAR-GRADE ACTIVATED CHARCOAL" l

PURPOSE-I To inform the Commission of the staff's intent to issue the subject generic letter. In the generic letter, the staff asks the licensees of operating nuc; ear power reactors to amend their facility technical specifications to reference either the American Society for Testing and Materials (ASTM) Standard D3803-1989," Standard Test Method for Nuclear-Grade Activated Carbon," or an alternate test protocol that has been demonstrated to give accurate and consistent results.

Additionally, licensees may propose another course of action, which would be subject to NRC review and approval. The objective is to ensure licensee compliance with the licensing bases of their respective facilities, as they relate to the onsite and offsite dose consequences of General Design Criterion (GDC) 19 of Appendix A to Part 50 of Title 10 of the Code of Federal Reaulations (10 CFR) and the guideline values of Subpart A of 10 CFR Part 100, respectively.

j g 11 It is the staff's intent to exercise enforcement discretion with licensees under certain conditions B

in the resolution of this matter.

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A copy of the proposed generic letter is attached (Attachmer.t 1).

I CONTACT:

John P. Segala, NRR/DSSA ll 415-1858 9906030117 990514 PDR SECY 99-132 R PDR

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f POLICY ISSUE May 14.1999 (InfOrrnation)

SECY-99-132 FOR:

The Commissioners FROM:

William D. Travers Executive Director for Operations

SUBJECT:

PROPOSED NRC GENERIC LETTER 99-XX, " LABORATORY TESTING OF NUCLEAR-GRADE ACTIVATED CHARCOAL" PURPO_SE:

To inform the Commission of the staff's intent to issue the subject generic letter. In the generic letter, the staff asks the licensees of operating nuclear power reactors to amend their facility technical specifications to reference either the American Society for Testing and Materials (ASTM) Standard D3803-1989," Standard Test Method for Nuclear-Grade Activated Carbon," or an alternate test protocol that has been demonstrated to give accurate and consistent results.

Additionally, licensees may propose another course of action, which would be subject to NRC review and approval. The objective is to ensure licensee compliance with the licensing bases of their respective facilities, as they relate to the onsite and offsite dose consequences of General Design Criterion (GDC) 19 of Appendix A to Part 50 of Title 10 of the Code of Federal Reculations (10 CFR) and the guideline values of Subpart A of 10 CFR Part 100, respectively.

lt is the staff's intent to exercise enforcement discretion with licensees under certain conditions in the resolution of this matter.

A copy of the proposed generic letter is attached (Attachment 1).

CONTACT:

l John P. Segala, NRR/DSSA 415-1858 q

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. The Commissioners 2

BACKGROUND:

Safety-related air-cleaning units used in the engineered safety feature (ESF) ventilation systems of nuclear power plants reduce the potential onsite and offsite consequences of a radiological accident by adsorbing radiolodine. The laboratory test acceptance criteria contain a safety factor to ensure that the efficiency assumed in the licensee's design-basis dose analysis is still valid at the end of the operating cycle. To ensure that the charcoal filters used in these systems will perform in a manner that is consistent with the licensing basis of a facility, most licenseos have requirements in their facility technical specifications'(TS) to periodically test (in a latoratory) samples of charcoal taken from the air-cleaning units.

DISCUSSION:

The NRC has been working with the industry on the problems associated with the laboratory testing of charcoal since the early 1980s. In 1982, the American Society of Mechanical Engineers (ASME) Committee on Nuclear Air and Gas Treatment (CONAGT) conducted an inter laboratory comparison test using ASTM D3803-1979 (the standard then being endors.ed by the NRC) and found that seven U.S. laboratories and eight foreign laboratories obtained vastly different results when testing samples of the same charcoal. After efforts to resolve the differences failed, the NRC contracted with the Idaho National Engineering Laboratory (INEL) to assess the problem. As a result of this assessment, the NRC issued Information Notice (IN) 87-32," Deficiencies in the Testing of Nuclear-Grade Activated Charcoal." Through IN 87-32, the NRC informed licensees of deficiencies in charcoal testing, specifically noting serious problems with the capabilities of the testing laboratories and with the testing standard ASTM D3803-1979. The information notice indicated that the protocol developed by INEL could be utilized for performing the laboratory test until the 1979 standard could be revised. The ASTM completed the revision and issued it in December 1989 as ASTM D3803-1989. The staff considers ASTM D3803-1989 to be the most accurate and most realistic protocol for testing charcoal in ESF ventilation systems because it offers the greatest assurance of accurately and consistently determining the capability of the charcoal.

The staff intends to exercise enforcement discretion, consistent with Section Vll.B.6 of the enforcement policy, provided that certain actions are taken by addressees, including the submittal of a TS amendment request and the testing of charcoal samples in accordance with ASTM D3803-1989, until such time that the TS amendment request is approved by the NRC.

The Commission endorsed the use of enforcement discretion under the conditions outlined in the generic letter in a staff requirements memorandum (SRM) that was issued on February 5, 1998, in response to SECY-97-299, " Laboratory Testing of Nuclear-Grade Activated Charcoal,"

dated December 24,1997. This SRM also directed the staff to consult with the Commission before issuance of the final generic letter if the staff received public comments that resulted in significant changes to the actions presented in the generic letter.

L Subsequent to receiving the SRM noted above, a notice of opportunity for public comment was published in the Federa/ Register (63 FR 9581) on February 5,1998. The staff received 23 letters in response to the FederalRegister notice, and identified 130 comments. Of these 130 comments,83 were redundant, leaving 47 distinct comments. Attachment 2 contains the staff's responses to the 47 distinct public' comments and identifies whether, and how, the generic letter was revised to reflect a particular comment. As a result of the public comments,

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- ' The Commissioners 3

the majority of the changes to the generic letter concemed reducing unnecessary burden on

- addressees (licensees). _ Specifically, the conditions under which enforcement discretion will be exercised have been changed to allow up to 180 days to submit a TS an'endment request, to allow testing of the charcoal sample at the next required laboratory surveillance test, and to allow a safety factor as low as 2 to be applied to the charcoal tilter efficiency assumed in an addressee's design-basis dose analysis to determine the operability of the charcoal. The other -

changes were technical and editorial in nature.

On the basis of available laboratory test results for more than 50 charcoal samples, there were significant differences in filter efficiencies for about 15 to 20 percent of the tested samples when comparing the test results from ASTM D3803-1979 and ASTM D3803-1989. This difference in filter efficiency can result i.n calculated design-basis doses to the control room operators exceeding the GDC 19 limits by as much as a factor of 1.5 to 2 and offsite doces from a filtered pathway increasing by as much as a factor of 10 to 15. However, the staff believes that most charcoal in use is not degraded to an extent that would adversely affect control room habitability or public health and safety. Therefore, given the low probability of a design-basis accident and the conservatism inherent in the design-basis dose calculations including the conservatism in the design-basis source term, this issue is not an immediate safety concem, and the staff believes that the time frames noted in the generic letter for resolution of this matter are justified.

The generic letter was reviewed by the Committee To Review Generic Requirements (CRGR) during its meeting (No. 333) on December 8,1998. The staff ' incorporated the CRGR comments into the generic letter, with one variation. The generic letter originally cited 10 CFR 50.54(f) as the basis for requiring responses from the addressees. However, under issue IV.F of the Chairman's tasking memo, the staff has reexamined the basis for invoking $50.54(f).

The staff has decided that since the issue being addressed is not an immediate safety concem, j

} $50.54(f) would not be cited for this generic communication.

i When $50.54(f) is cited, however, it imposes a requirement on the staff. The regulation requires the preparation of the rationale for an information collection to ensure that the burden

- to be imposed on the respondents is justified in view of the potential safety significance of the issue being addressed; this analysis is not required if information is sought to verify licensee compliance with the licensing basis for a facility. Nevertheless, a section has been added to the generic letter that gives the staff's rationale for the information collection; this section is titled

" Reasons for Requested Information." This is an appropriate standard that should be applied to all generic communication information requests, even if 950.54(f) is not cited in the generic communication.

The Office of Enforcement willissue an enforcement guidance memorandum to reflect the enforcement discretion described in the generic letter.

SUMMARY

The staff intends to issue this generic letter approximately 5 working days after the date of this

information paper.

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9 The Comrnissioners 4

COORDINATION:

- The CRGR has endorsed the proposed final generic letter, including the~ staff's decision not to cite $50.54(f).'

The Office of the General Counsel has reviewed this generic letter and has no legal objections l

to its content.

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1 William D. Travers l

Executive Director for Operations

- Attachments:

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1. Proposed Generic Letter, " Laboratory Testing of Nuclear-Grade Activated Charcoal" 2.. Public Comment Resolution and Staff Response DISTRIBUTION:

Commissioners OGC OCAA OIG OPA OCA ACRS CIO CFO EDO l

REGIONS SECY l

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E ATTACHMENT 1

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OMB Control No.: 3150-0011 UNITED STATES l

NUCLEAR REGULATORY COMMISSION OFFICE OF NUCLEAR REACTOR REGULATION WASHINGTON, D.C. 20555-0001 l

(Date}

NRC GENERIC LETTER 99-XX:

LABORATORY TESTING OF NUCLEAR-GRADE ACTIVATED CHARCOAL Addressees A!! holders of operating licenses for nuclear power reactors, except those who have permanently ceased operations and have certified that fuel has been permanently removed from the reactor vessel.

Purpose The U.S. Nuclear Regulatory Commission (NRC) is issuing this generic letter to:

(1)

Alert addressees that the NRC has determined that testing nuclear-grade activated charcoal to standards other than American Society for Testing and Materials (ASTM) D3803-1989, " Standard Test Method for Nuclear-Grade Activated Carbon,"

does not provide assurance for complying with the current licensing basis as it relates to the dose limits of General Design Criterion (GDC) 19 of Appendix A to Part 50 of Title 10 of the Code of Federal Reculations (10 CFR) and Subpart A of 10 CFR i

Part 100.

(2)

Request that all addressees determine whether their technical specifications (TS) reference ASTM D3803-1989 for charcoal filter laboratory testing. Addressees whose TS do not reference ASTM 03803-1989 should either amend their TS to reference ASTM D3803-1989 or propose an alternative test protocol and provide the information discussed in the requested actions.

(3)

Alert addressees of the stafi's intent to exercise enforcement discretion under certain conditions.

(4)

Request that all addressees send the NRC written responses to this generic letter, l

relating to implementation of the requested actions.

Backaround Safety-related air-cleaning units used in the engineered safety features (ESF) ventilation systems of nuclear power plants reduce the potential onsite and offsite consequences of a radiological accident by adsorbing radiciodine. To ensure that the charcoal filters used in thxse i

GL 97-XX (Date)

Page 2 of 11 systems will perform in a manner that is consistent with the licensing basis of a facility, most licensces have requirements in their facilityTS to periodically test (in a laboratory) samples of charcoal taken from the air-cleaning units.

The NRC's and the nuclear industry's understandings of the appropriate laboratory tests for nuclear-grade charcoal have evolved over the years since the issuance of Regulatory Guide (RG) 1.52, " Design, Testing, and Maintenance Criteria for Postaccident Engineered-Safety-Feature Atmosphere Cleanup System Air Filtration and Adsorption Units of Light-Water-Cooled Nuclear Power Plants," which is referenced in many plant TS. It was initially assumed that high-temperature /high-relative-humidity (RH) conditions were the most severe. Later, with more testing experience, it became clear that the most conservative test is at low temperature /high humidity. The use of outdated test protocols or inappropriate test conditions can lead to an overestimation of the charcoal's ability to adsorb radioiodine following an accident.

Problems associated with the performance of the laboratory test of charcoal under inappropriate test conditions were discussed in Attachment 1 of Information Notice (lN) 86-76,

" Problems Noted in Control Room Emergency Ventilation Systems." Attachment 1, " Summary of Control Room Habitability Reviews," noted that charcoal was being tested at much higher temperatures than any expected during the course of an accident, and that the performance of the laboratory test at that temperature can result in erroneously high efficiency measurements, in 1982, the American Society of Mechanical Engineers (ASME) Committee on Nuclear Air and Gas Treatment (CONAGT) conducted an inter-laboratory comparison test using ASTM D3803-1979 and found that seven U.S. laboratories and eight foreign laboratories

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obtained vastly different results when testing samples of the same charcoal. After efforts to resolve the differences failed, the NRC contracted with EG&G at Idaho National Engineering Laboratory (INEL) to assess the problem. As a result of this assessment, the NRC issued IN 87-32, " Deficiencies in the Testing of Nuclear-Grade Activated Charcoat." Through IN 87-32, the NRC informed licensees of deficiencies in the testing of nuclear-grade charcoal, specifically noting serious problems with the capabilities of the testing laboratories and with the testing standard (ASTM D3803-1979). The NRC contractor detailed the specific problems in its technical evaluation report, EGG-CS-7653, " Final Technical Evaluation Report for the NRC/INEL Activated Carbon Testing Program." Specifically, EG&G reported that ASTM D3803-1979 had unacceptable test parameter tolerances and instrument calibration requirements, and that ASTM D3803-1979 was nonconservative in not requiring humidity pre-equilibration of used charcoal. The information notice indicated that the protocol developed by EG&G could be utilized for performing the laboratory test until the D-28 committee responsible for ASTM D3803 revised the standard. The committee completed the revision and issued it in December 1989. The problems associated with the testing laboratories were resolved after the number of U.S. firms performing such tests dropped from seven to the current two.

On April 29,1993, representatives from ASME and CONAGT met with the NRC staff to express their concerns about laboratory testing of charcoal. CONAGT discussed the variation in laboratory test results obtained (methyl iodide penetration) when temperature, RH, face velocity, bed depth, test protocol, and impregnate were varied. CONAGT stated that the 1989 version of ASTM D3803 is the only acceptable test method for TS applications and compared

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GL 97-XX

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Page 3 of 11

- the results of laboratory tests performed using the 1986 version of ASTM D3803 (which is the 1979 version with editorial changes) to results using the 1989 version. The results from the 1986 protocol showed significantly higher iodine-removal capabilities than the results from the 1989 version, in addition, CONAGT indicated that testing charcoal at temperatures greater than 30 *C [86 'F]

almost always results in the charcoal meeting the TS acceptance criteria, even when the charcoal is deficient. To support this premise, CONAGT presented the results of laboratory tests conducter'ot temperatures of 30 *C [86 *F],80 *C [176 'F], and 130 *C [266 'F]. The data show sigtscant increases in iodine-removal capabilities as the test temperature increases.

CONAGT indicated that all systems located outside of containment should be tested at 30 *C [86 *F), which is more representative of the limiting accident conditions. Tests conducted i

- at 80 'C [176 'F] or 130 *C [266 'F] are inappropriate because tests at these temperatures result in the regeneration of the charcoal. As the temperature of the charcoalis increased, there is an increase in the reaction rate, which results in the charcoal being able to adsorb more j

iodine than it could at lower temperatures. Therefore, testing at the elevated temperatures I

results in an overestimation of the actual iodine-removal capability of the charcoal, and testing at 25 *C [77 'F] or 30 *C [86 'F] gives results that represent a more realistic assessment of the capability of the charcoal. CONAGT concluded its presentation by stating that the major problems associated with the laboratory test of charcoal are the designation of the test protocol i

and the TS that designate the test to be performed.

. On November 6,1996, the staff visited the two remaining laboratories that test nuclear-grade activated charcoal, NCS Corporation and NUCON Intemational, Inc. Both laboratories have

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resolved the poor reproducibility problem identified in the EG&G report by performing all tests

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l with calibrated equipment that is capable of maintaining the tight tolerances of the test

- parameters as specified in ASTM D3803-1989.- Tight tolerances are very important when tests are performed at high RH, because slight variations in RH result in unacceptably large differences in the tested efficiency of the charcoal.

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Discussion Although some licensees have changed their TS to reference the latest testing standard (ASTM D3803-1989), many still use outdated standards and/or test conditions that may overestimate the capability of the charcoalin their ESF systems. As a result, the ability of the charcoal filters in these systems to perform in a manner consistent with the licensing basis for the facility may be in question.

The licensees of four plants (V.C. Summer, Davis-Besse, Oconee, and Brunswick) determined that the tests they performed were not in compliance with their TS and submitted emergency TS amendments (see Enclosure 1 for details). As a result of the emergency TS changes, the staff has performed an intamal survey of the TS of operating plants to determine whether other plants have the potential for similar compliance problems. The survey indicated that at least

- one-third of operating reactor licensees may be out of compliance with their TS because, although the plants

TS reference RG 1.52 or American National Standards Institute (ANSI)

N509-1976, " Nuclear Power Plant Air-Cleaning Units and Components," the licensees may I

GL 97-XX (Date}

Page 4 of 11 have used later versions of the standards for the laboratory tests of their nuclear-grade charcoal in order to achieve more accurate testing results. On the basis of this survey, the staff established the following four groups of plants:

(1) plants in compliance with their TS that test in accordance with ASTM D3803-1989 (2) plants in compliance with their TS that test in accordance with a test protocol other than ASTM D3803-1989 (3) plants not in compliance with their TS that test in accordance with ASTM D3803-1989 (4) plants not in compliance with their TS that test in accordance with a test protocol other than ASTM D3803-1989 Licensees in Group 1 have TS that require charcoal to be tested in accordance with ASTM D3803-1989, which adequately demonstrates the capability of the charcoal. As discussed in Enclosure 1, the staff considers ASTM D3803-1989 to be the most accurate and most realistic protocol for testing charcoal in ESF ventilation systems because it offers the greatest assurance of accurately and consistently determining the capability of the charcoal.

For example, it requires the test to be performed at a constant low temperature of 30 'C [86 'F]; it provides for smaller tolerances in temperature, humidity, and air flow; and it has a humidity pre-equilibration.

Licensees in Group 2 have TS that require charcoal to be tested in accordance with test standards other than ASTM D3803-1989. On the basis of available laboratory test results for more than 50 charcoal samples, there were significant differences in filter efficiencies for about 4

15 to 20 percent of the tested samples when comparing the test results from ASTM D3803-1979 and ASTM D3803-1989. When the charcoal samples were tested in accordance with ASTM D3803-1979, they appeared to have high efficiencies. However, when the same charcoal samples were tested in accordance with ASTM D3803-1989, significant reduction in efficiency was noted. Depending on the system arrangement, this reduction in filter efficiency can result in calculated doses to the control room operators exceeding the GDC 19 limits by as much as a factor of 1.5 to 2. For pressurized-water reactors (PWRs) with secondary containments and for all boiling-water reactors (BWRs), this reduction in filter efficiency can result in offsite doses from a filtered pathway increasing by as much as a factor

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of 10 to 15. As a result, the testing of nuclear-grade activated charcoal to standards other than ASTM D3803-1989 does not provide assurance for complying with the plant's licensing basis as it relates to the dose limits of GDC 19 and Part 100.

In addition, the staff has determined that ASTM D3803-1989 should be used for both new and used charcoal because it allows for accurately monitoring the degradation of the charcoal over time. The original rationale for testing used and new charcoal differently was the belief that a long equilibration period would regenerate the used charcoal by removing contaminants adsorbed by the charcoal during normal plant use. However, an EG&G technical evaluation report, described in Enclosure 1, demonstrated that this is not true. As a result, ASTM D3803-1989 specifies testing both used and new charcoalin the same manner.

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1 GL 97-XX

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Page 5 of 11 Currently, before shipping, suppliers test most new charcoal with the ASTM D3803-1989

. protocol at 30 *C [86 *F) and 95 percent RH in addition to the test protocol and test conditions the addressee records on the purchase order. The results from the new charcoal tested via ASTM D3803-1989 present a solid baseline for the initial capability of the charcoal. Using ASTM D3803-1989 to test used charcoal is a very accurate and reproducible method for determining the capability of the charcoal. By comparing the results of the tests performed on used charcoal with the baseline test performed on new charcoal, the addressee can be certain of the charcoat's level of degradation.

' Analyses of design-basis accidents assume a particular ESF charcoal filter adsorption efficiency when calculating offsite and control room operator doses. Licensees then test charcoal filter samples to determine whether the filter adsorber efficiency is greater than that assumed in the design-basis accident analysis. The laboratory test acceptance criteria contain a safety factor to ensure that the efficiency assumed in the accident analysis is'still valid at the end of the operating cycle. Because ASTM D3803-1989 is a more accurate and demanding test than olcier tests, addressees that upgrade their TS to this new protocol will be able to use a

. safety factor as low as 2 for determining the acceptance criteria for charcoal filter efficiency

(see note in Enclosure 2 for further discussion). This safety factor can be used for systems with or without humidity control because the lack of humidity control is already accounted for in the test conditions (systems without humidity control test at 95 percent RH and systems with humidity control can_ test at 70 percent RH). The staff has previously approved reductions in the safety factor for plants adopting the ASTM D3803-1989 standard on a case-by-case basis.

(The staff plans to make conforming changes to RG 1.52.)

The licensees that received emergency TS changes were in Groups 3 and 4. Licensees in

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Groups 3 and 4 have TS that require charcoal to be tested in accordance with RG 1.52 or

. ANSI N509-1976, and are not in compliance with their TS because the specified test protocol cannot be successfully completed as discussed in Enclosure 1. ~ These licensees are either (1) testing in accordance with the desired ASTM D3803-1989 (Group 3) or (2) using earlier revisions of ASTM D3803 or an older standard, which they believe are acceptable (Group 4).

The staff does not have confidence that the results from RG 1.52 or ANSI N509-1976 meet the

. Intent of the TS, which is to ensure that the doses are within the required limits. Therefore,

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' licensees in these groups have not adequately demonstrated compliance with their licensing basis as it relates to the dose limits of GDC 19 and Part 100.

- The staff believes that (1) conflicting guidance, (2) complex and ambiguous standards, and

. (3) licensee belief that using later versions of the ASTM D3803 standard would satisfy TS requirements, contributed to confusion regarding charcoal testing. These factors may explain why licensees did not adopt ASTM D3803-1989 (see Enclosure 1 for further discussion), in addition, on the basis of the available laboratory test results, the staff believes that most charcoal in use is not degraded to an extent that would adversely affect control room habitability

. or public health and safety. This confidence in charcoal performance, the low probability of a design-basis accident and the conservatism inherent in the design-basis dose calculations, including the conservatism in the design-basis source term, justify the time frames for the tresolution of this matter. Therefore, the staff intends to exercise enforcement discretion, 1

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GL 97-XX (Date}

Page 6 of 11 consistent with Section Vll.B.6 of the Enforcement Policy, for all addressees in Groups 2,3, and 4, provided that A TS amendment request referencing ASTM D3803-1989 or an alternate test protocol is e

submitted to the NRC within 180 days of the date of this letter; At the next required laboratory surveillance test of a charcoal sample that is 60 or more e

days after the date of this generic letter, charcoal samples are tested in accordance with ASTM D3803-1989 or all of the charcoalis replaced with new charcoal that has been tested in accordance with ASTM D3803-1989. In all cases, the resulta should meet the acceptance criterion that is derived from applying a safety factor as low as 2 (see the note ir. Enclosure 2) to the charcoal filter efficiency assumed in the addressee's design-basis dose analysis; and The charcoal samples continue to be tested in accordance with ASTM D3803-1989, in lieu e

of the current TS-required laboratory testing, until the TS amendment is approved by the NRC.

i Licensees in Group 2 have been complying with their TS by testing their charcoal in accordance with their TS. Therefore, enforcement discretion is not required for past surveillance testing.

However, the staff will exercise enforcement discretion for licensees in Poup 2 to eliminate j

unnecessary testing of charcoal samples to both ASTM D3803-1989 anc r.e current TS testing protocol during the period of time between issuance of the generic letter and approval of the TS amendment.

Reauested Actions 1

1.

Within 180 days of the date of this generic letter, submit a written response to the NRC describing your current TS requirements for the laboratory testing of charcoal samples for each ESF ventilation system including the specific test protocol, temperature, RH, charcoal bed thickness, total residence time per bed depth, and penetration at which the TS require the test to be performed. If your current TS specifically require laboratory testing of charcoal samples in accordance with the ASTM D3803-1989 protocol at 30 *C [86 'F), and you have been testing in accordance with this standard, then you only need to address this requested action (i.e. no TS amendment or additional testing is required).

2.

If you choose to adopt the ASTM D3803-1989 protocol, submit a TS amendment request to require testing to this protocol within 180 days of the date of this generic letter. The request should contain the test temperature, RH, and penetration at which the proposed TS will require the test to be performed and the basis for these values, if the system has a face velocity greater than 10 percent of 0.203 m/s [40 ft/ min), then the revised TS should specify the face velocity. Also, indicate when the next laboratory test is scheduled to be performed. (Enclosure 2 is a sample TS that the NRC considers acceptable.)

3.

If you are proposing an altemate test protocol, address the attributes discussed below and submit a TS amendment request to require testing to this alternate protocol within 180 days of the date of this generic letter. The request should contain the test

GL 97-XX

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Page 7 of 11 temperature, RH, and penetration at which the proposed TS will require the test to be performed and the basis for these values. If the system has a face velocity greater than 10 percent of 0.203 m/s [40 ft/ min], then the revised TS should specify the face velocity.

Also, indicate when the next laboratory test is scheduled to be performed.

The following information should be submitted for staff review to determine the acceptability of the alternate protocol:

1.

summary of the test method 2.

precision of the method 3.

description of the test apparatus along with tolerances 4.

parameter specifications 5.

material requirements 6.

hazards 7.

preparation of the apparatus before initiation of the test 8.

calibration requirements of the test equipment 9.

test procedare

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10. manner of calculating penetration and error

11. repeatability and reproducibility of the results for 1 percent and 10 percent penetration and the penetration at a 95 percent confidence interval for charcoal tested at 70 percent RH and at 95 percent RH

12. bias associated with the method

13. results from at least two laboratories which demonstrate that the alternate test protocol achieves results that are consistent with, or more conservative than, results cssociated with ASTM D3803-1989.

The demonstration identified in item 13 above should be based upon a series of tests comparing the alternate test protocol and ASTM D3803-1989, and it should apply to both new and used charcoal tested at 70 percent RH and at 95 percent RH. If an addressee chooses to test its charcoal samples at actual accident conditions which are different from the test conditions specified in ASTM D3803-1989, then that test should be treated as an attemate protocol. At least two laboratories should be used in determining the acceptability of the alternate protocol. One laboratory should be used to develop the alternate protocol and the other to demonstrate the repeatability and reproducibility of the alternate protocol. The two laboratories should be able to L

GL 97-XX

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Page 8 of 11 demonstrate that the altemate protocol is at least as conservative as ASTM D3803-1989, and should be able to perform the ASTM D3803-1989 test and j

achieve repeatable and reproducible results 4.

At the next required laboratory surveillance test of a charcoal sample that is 60 or more days after the date of this generic letter, test your charcoal samples in accordance with ASTM D3803-1989 or replace all of the charcoal with new charcoal that has been tested in accordance with ASTM D3803-1989. In all cases, the results should meet the acceptance criterion that is derived from applying a safety factor as low as 2 (see the note in 1 ) to the charcoal filter efficiency assumed in your design-basis dose analysis and the charcoal samples should continue to be tested in accordance with ASTM D3803-1989, in lieu of the current TS-required laboratory testing, until the TS amendment is approved by the NRC.

5.

Addressees who choose not to do the above actions are requested to notify the NRC in i

writing of their decision, as soon as a decision is reached but no later than 60 days from the date of this generic letter. The 60 day written response should also discuss (1) addressee plans to pursue a proposed alternative course of action (including the basis for establishing its acceptability), (2) the schedule for submitting that proposal for NRC staff review (that proposal should be submitted to the NRC no later than 180 days from the date of this generic letter), and (3) the basis for continued operability of affected systems and components unti: such time that the proposed alternative course of action is approved by

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the NRC.

Address the written response to the U.S. Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington, D.C. 20555-0001, in addition, send a copy to the appropriate regional administrator.

Reasons for Reouested information This generic letter requests that addressees submit information. The requested information will enable the NRC staff to make a determination that addressees are testing the nuclear-grade activated charcoal of their ESF ventilation systems in accordance with a suitable testing standard to ensure that the charcoal filters are capable of performing their required safety function and that the licensing bases of their respective facilities regarding onsite and offsite dose consequences continue to be satisfied.

The NRC erroneously assumed that existing charcoal filter test protocols other than i

ASTM D3803-1989 would be sufficient to assure accurate and reproducible results. In fact, the available laboratory test results demonstrate that existing test protocols other than ASTM D3803-1989 do not provide accurate and reproducible test results and may overestimate i

the capability of the charcoal. Therefore, the requested information is necessary for the NRC staff to make an accurate assessment of the charcoal filter capability, in order to assure compliance with the plant's licensing basis as it relates to the dose limits of GDC 19 and j

Part 100, including commitment to the resolution of TMI Action Plan item Ill.D.3.4.

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GL 97-XX

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Page 9 of 11 Backfit Discussion Appendix A to 10 CFR Part 50, " General Design Criteria (GDC) for Nuclear Power Plants," and

' the plant safety analyses require and/or commit that licensees design and test safety-related structures, systems, and components to offer adequate assurance that they can perform their -

safety functions. Specifically, GDC 19 of Appendix A to 10 CFR Part 50 specifies dose limits to ensure'that control room operators are provided with adequate radiation protection under accident conditions. Following the accident at Three Mile Island (TMI). TMl Action Plan Item lil.D.3.4 " Control Room Habitability Requirements," as specified in NUREG-0737,

" Clarification of TMI Action Plan Requirements," required all licensees to perform evaluations

-and identify appropriate modifications to ensure that control room operators are adequately

. protected from the release of radioactive gases and that the nuclear power plant can be safely operated or shut down under design-basis accident conditions (GDC 19). When modifications were proposed by licensees, the NRC issued orders confirming licensee commitments. ' As a result, alllicensees are required to meet the dose limits of GDC 19. In addition, Subpart A of

10,CFR Part 100 specifies reference dose values that can be used in evaluating the suitability of proposed sites for nuclear power plants with respect to potential reactor accidents that could

' result in the release of significant quantities of radioactive fission products. The expectation is that the site location and the engineered safety features included as safeguards against the hazardous consequences of an accident, should one occur, ensure a low risk of puolic exposure.- In this regard, licensees commit to dose limits that can be used as the basis for assessing the performance of safety-related structures, systems, and components.

Accordingly, to ensure continued compliance with facilities' licensing bases, as they relate to the -

dose limits of GDC 19 and Part 100, a valid test protocol is necessary.

E l

The actions requested in this generic letter are considered compliance backfits under the l

provisions of 10 CFR 50.109(a)(4)(i). The compliance exception addresses, inter alia, situations where the licensee has failed to meet known and established Commission standards because of mistake of fact. See 50 FR 38103 (September 20,1985). 'The NRC erroneously -

assumed that existing charcoal filter test protocols other than ASTM D3803-1989 would be sufficient to assure accurate and reproducible results. In fact, the available laboratory test results demonstrate that existing test protocols other than ASTM D3803-1989 do not provide accurate and reproducible test results and may overestimate the capability of the charcoal.

Therefore, the proposed backfit, which would apply only to used charcoal filters, is necessary l

for accurate assessment of the charcoal filter capability, in order to assure compliance with the plant's licensing basis as it relates to the dose limits of GDC 19 and Part 100, including commitment to the resolution of TMi Action Plan item til.D.3.4. The NRC staff has adopted a l

l new staff position by endorsing the ASTM D3803-1989 testing standard for referencing in plant l~

- TS because ASTM D3803-1989 is the' only available testing standard the staff is aware of that

- provides accurate and reproducible test results. In accordance with the provisions of 10 CFR 50.109(a)(4)(i), regarding compliance backfits, a full backfit analysis was not performed. However, an evaluation was performed in accordance with NRC procedures, -

including a statement of the objectives, the reasons for the requested actions, and the basis for invoking the compliance exception, and is reflected in this backfit discussion.

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GL 97-XX (Date}

Page 10 of 11

. Federal Reaister Notification' A notice of opportunity for public comment was published in the FederaiRegisteron February 25,1998.: Comments were received from 18 licensees,2 industry organizations, i 2 charcoal testing laboratories, and 1 individual. The staff considered all comments that were received, including comments received as late as May 26,1998. Copies of the staff evaluation of these comments are avaliable in the Public Document Room.

Paperwork Reducten Act Statement This generic letter contains information collections that are subject to the Paperwork Reduction Act of 1995 (22 U.S.C. 3501 et seq.). These information collections were approved by the Office of Management and Budget (OMB), approval number 3150-0011, through 4 August 31,2000.

The public reporting burden for this collection of information is estimated to average 250 hours0.00289 days 0.0694 hours 4.133598e-4 weeks 9.5125e-5 months

. per response, including the time for reviewing instructions, searching existing data. sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. The U.S. Nuclear Regulatory Commission is seeking public comment on the potential impact of the collection of information contained in the generic letter and on the

' following issues:

. (1), is the proposed collecten of information necessary for the proper performance of the functions of the NRC, including considerat!on of whether the information will have practical utility?:

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, (2) is the estimate of burden accurate?

. (3) : Is there a way to enhance the quality, utility, and clarity of the information to be collected?

- (4) How can the burden of the collection of information be minimized, including consideration of the use of automated collection techniques?

Send comments on any aspect of this collection of information, including suggestions for =

reducing this burden, to the information and Records Management Branch, T-6 F33, U.S.

' Nuclear Regula$ory Commission, Washington, D.C. 20555-0001, and to the Desk Officer,

- Office of Information and Regulatory Affairs, NEOB-10202 (3150-0011), Office of Management and Budget, Washington, D.C. 20503.

. The NRC may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid OMB control number.

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GL 97-XX

{Date)

Page 11 of 11 if you have any questions about this matter, please contact the technical contact listed below or the appropriate Office of Nuclear Reactor Regulation (NRR) project manager.

Sincerely, David B. Matthews, Director Division of Regulatory improvement Programs Office of Nuclear Reactor Regulation Technical contact:

John P. Segata, NRR 301-415-1858 Internet: jps1@nrc. gov Lead project manager: Brenda L. Mozafari, NRR 301-415-2020 internet: blm@nrc. gov i

Enclosures:

(1) Background Information on the Laboratory Testing of Nuclear-Grade Activated Charcoal

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(2) Sample Technical Specifications j

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O BACKGROUND INFORMATION ON THE LABORATORY TESTING OF NUCLEAR-GRADE ACTIVATED CHARCOAL Charcoal Testina Reauirements Analyses of design-basis accidents assume a particular engineered safety features (ESF) charcoal filter adsorption efficiency when calculating offsite and control room operator doses.

Licensees then test charcoal filter samples to determine whether the filter adsorber efficiency is greater than that assumed in the design-basis accident analysis. The laboratory test acceptance criteria contain a safety factor to ensure that the efficiency assumed in the accident analysis is still valid at the end of the operating cycle.

Guidance on the frequency of, and the test method for, the laboratory testing of charcoal appears in various documents, including all revisions of Regulatory Guide (RG) 1.52, " Design, Testing, and Maintenance Criteria for Postaccident Engineered-Safety-Feature Atmosphere Cleanup System Air Filtration and Adsorption Units of Light-Water-Cooled Nuclear Power Plants," and other NRC documents on plant technical specifications (TS). Guidance on the laboratory test protocol appears in such standards as American National Standards Institute (ANSI) N509, " Nuclear Power Plant Air-Cleaning Units and Components"; ANSI N510, " Testing of Nuclear Air-Cleaning Systems"; Military Specification RDT M 16-1T, " Gas Phase Adsorbents for Trapping Radioactive lodine and lodine Components"; and American Society for Testing and Materials (ASTM) Standard D3803, " Standard Test Method for Nuclear-Grade Activated Carbon."

All of the standards describe a pre-equilibration period, a challenge period, and an elution period. During the pre-equilibration (pre-sweep) period, the charcoalis exposed to a flow of air controlled at the test temperature and relative humidity (RH) before the challenge gas is fed through the charcoal. The pre-equilibration period ensures that the charcoal has stabilized at the specified test temperature and RH for a period of time, which results in the charcoal becoming saturated with moisture before it is challenged with methyl iodide. During the challenge period, air at the test temperature and RH with radio-labeled methyl iodide is injected through the charcoal beds to challenge the capability of the charcoal. During the elution (post-sweep) period, air at the test temperature and RH is passed through the charcoal beds to evaluate the ability of the charcoal to hold the methyl iodide once it is captured.

The ASTM D3803-1989 standard has two additional testing periods that are not required by other standards: the stabilization period and the equilibration period. During the stabilization period, the charcoal bed is brought to thermal equilibrium with the test temperature before the start of pre-equilibration. During the equilibration period, air at the test temperature and RH is passed through the charcoal beds to ensure the charcoal adsorbs all the available moisture before the feed period. During this period, the system is more closely monitored than in the pre-equilibration period to ensure that all parameters are maintained within their limits.

Depending upon the plant's TS, typical test temperatures are usually one of the following:

25 *C [77 'F],30 *C [86 'F],80 *C [176 *F], or 130 *C [266 'F). In addition, the TS usually (.

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- require that the test be conducted at 70 percent RH if the ESF system controls the RH to

70 percent or less, or at 95 percent if the RH is not controlled to 70 percent.

)

The standard technical specifications (STS) and many plant-specific TS specify Regulatory

? Position C.6.a of RG 1.52, Revision 2, as the requirement for the laboratory testing of the r'"

charcoal.. Regulatory Position C.6.a refers to Table 2 of RG 1.52. Table 2 references Test 5.b

- of Table 5-1 of ANSI N509-1976,

Nuclear Power Plant Air-Cleaning Units and Components.*

. Test 5.b references the test method from paragraph 4.5.3 of Military Specification RDT M 16-1T,

Gas Phase Adsorbents for Trapping Radioactive lodine and lodine Components * (date not indicated), but specifies that the test is to be conducted at

. 80 *C [176_*F] and 95 percent RH with preloading and postloading sweep at 25 *C [77 'F].

This test is referred to as the "25-80-25 test." The essential elements of this test are as follows:

, - e ? 70 percent or 95' percent RH

< e ' 5-hour pre-equilibration (pre-sweep) time, with air at 25 *C [77 *F] and plant-specific RH

. e ~ 2-hour challenge, with gas at 80 *C [176 *F) and plant-specific RH A 2-hour elution (post-sweep) time, with air at 25 *C [77.*F] and plant-specific RH o

- The latest acceptable methodology for the laboratory testing of the charcoal is ASTM Standard D3803-1989,

Standard Test Method for Nuclear-Grade Activated Carbon."

- ASTM D3803-1989 is updated guidance based cn an NRC verification and validation effort

- regarding ASTM D3803-1979, which is updated guidance based on RDT M 16-1T. The essential elements of the ASTM D3803-1989 test are as follows:

e 70 percent or 95 percent RH 2-hour minimum thermal stabilization, at 30 *C [86 *F]

e e 16-hour pre-equilibration (pre-sweep) time, with air at 30 *C [86_*F) and plant-specific RH

,. e hour equilibration time, with air at 30 *C [86 *F) and plant-specific RH

- e 41-hour challenge, with gas at 30 *C [86 *F] and plant-specific RH

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1-hour elution (post-sweep) time,'with air at 30 *C [86 *F] and plant-specific RH

e The major' differences between the ANSI 'N509-1976 and ASTM D3803-1989 standards for-

-1

' charcoal testing are as follows:

1 MAJOR DIFFERENCES ASTM D3803-1989 ANSI N504-1976 Pre-Equilibration (Pre-Swoop) Temperature 30 *C [86 *F]

25 *C [77 "F]-

Challenge Temperature 30 *C [86 *F]

80 *C [176 *F]

Elution (Post-Sweep) Temperature 30 *C [86 'F]

25 *C [77 *F]

Total Pre-Test Equilibration -

-18 hours 5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months

Tolerances of Test Parameters Smaller Larger -

As stated above, ASTM D3803-1989 challenges the representative charcoal samples at 30.*C [86,*F] rather than at 80 *C [176 *F]. The quantity of water retained by charcoal is

dependent on temperature,'and less water is retained as the temperature rises. The water i,

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retained by the charcoal decreases its efficiency in adsorbing other contaminants. At i

30 *C [86 *F] and 95 percent RH, charcoal will retain about 24 to 25 weight-percent water. At 80 *C [176 "F] and 95 percent RH, charcoal retains only about 19 to 20 weight-percent water.

Because most charcoal is anticipated to be challenged at a temperature closer to 30 *C [86 *F) j rather than 80 *C [176 'F), the lowcr temperature test condition of ASTM D3803-1989 will yield more realistic results than would a test performed at 80 *C [176 *F].

ASTM D3803-1989 specifies a test temperature of 30 *C [86 *F] for both the pre-and post-test sweep rather than 25 *C [77 *F). There is little difference in the adsorption behavior of charcoal between these two temperatures. A temperature of 25 *C [77 'F]is more conservative; however, the increase from 25 *C [77 'F) to 30 *C [86 "F] does not represent a significant variation in the test results.

ASTM D3803-1989 provides results that are reproducible compared to RDT M 16-1T because it 3

has smaller tolerances on various test parameters, and it requires that the charcoal sample be pre-equilibrated for a much longer period. The longer pre-equilibration time is more conservative because it will completely saturate the representative charcoal sample, which ensures reproducibility of the results by having every charcoal sample begin the test at the same initial conditions. Therefore, testing in accordance with ASTM D3803-1989 will result in a more realistic prediction of the capability of the charcoal.

TS Testina Reference Laboratory tests of the charcoal are typically required (1) once every refueling outage, (2) when certain events occur that could adversely affect the ability of the charcoal to perform its intended function, and (3) following a defined period of ESF system operation. The TS require demonstration by laboratory testing that the charcoal is capable of performing at a level greater than that assumed in the NRC staff's safety evaluation report. If it fails to perform at that level, the charceal must be replaced.

The determination of the appropriate test conditions, test protocol, and acceptance criteria for laboratory testing of nuclear-grade activated charcoal is frequently not a straightforward process. It sometimes requires a complex journey through a number of documents to ascertain the appropriate test conditions, test protocol, and acceptance criteria. As described earlier, if the plant has STS, the STS reference Regulatory Position C.6.a of RG 1.52 for the requirements for the laboratory testing of charcoal. Regulatory Position C.6.a refers to Table 2 of the regulatory guide. Table 2 references Test 5 b of Table 5-1 of ANSI N509-1976. Test 5.b from Table 5-1 references the test method from paragraph 4.5.3 of RDT M 16-1T (date not indicated), but specifies that the test is to be conducted at 80 *C [176 *F) and 95 percent RH with pre-loading and postloading sweep at 25 *C [77 *F). This test is referred to as the "25-80-25 test."

Also contributing to the potential confusion are the various ways in which TS are written, and conflicting NRC guidance on testing, particularly NRC letters to the nuclear industry and NRC papers presented at national conferences. This problem arose from the evolving understanding of what constituted an appropriate test. At various times, the NRC has stated that the newest version of a standard can be used and the test can be conducted at a temperature of 30 *C [86 *F). At other times, the NRC indicated that the TS are requirements and that the tests must be pedormed at the 25-80-25 conditions. In various forums, the NRC has also stated that a technical argument may be made for using the newer standard. However, in some instances when newer standards were utilized to demonstrate conformance with the TS, the NRC required licensees to submit TS amendment requests because the newer standards were not referenced in the TS. Therefore, it is understandable that licensees may be confused about laboratory testing protocols, testing conditions, and acceptance criteria. As a result, many licensees are not testing charcoal in accordance with their TS, although the tests they conduct may be more conservative than the tests required by the TS.

l Additionally, the 25-80-25 test has difficulties in that none of the protocols in any version of l

RDT M 16-1T or ASTM D3803 addresses performing the laboratory test at multiple temperatures as required by ANSI N509-1976. If the test protocol described in paragraph 4.5.3 of RDT M 16-1T (1973) is followed verbatim, a thermal step change must be made after the 5-hour pre-equilibration period to increase the temperature from 25 *C [77 *F] to 80 *C [176 "F]

for the challenge period. The problem with such thermal step changes is that they result in condensation forming on the charcoal. The condensation of free water in the sample bed is cause for aborting the test, according to the 1977 version of RDT M 16-1T and subsequent versions of ASTM D3803. Therefore, the 25-80-25 test cannot be performed pursuant to any existing test protocol.

b Because paragraph 4.5.3 cannot be followed verbatim, a few licensees have changed the i

25-80-25 test to thermally equilibrate the charcoal before introducing the challenge gas.

Following the pre-sweep conditioning at 25 *C [77 *F), the bed temperature is raised to 80 *C [176 *F] before introducing the challenge gas. Although such testing does not cause condensation in the test rig, it is not acceptable because the results are not easily reproducible, and even when the test is successfully completed, the results may not be conservative.

Section 2 of ANSI N509-1976 states for the various documents that supplement ANSI N509 that the issuance of a document in effect at the time of the purchase order shall apply unless otherwise specified in the case of charcoal, the purchase order date could be considered the date that the charcoalis procured. Therefore, TS that have the STS wording may allow the licensee the flexibility to use a more recent laboratory protocol than the 1973 version of RDT M 16-1T, depending on the procurement date for the charcoal, without a TS change.

However, although the flexibility of protocol selection exists, the requirement to perform a 25-80-25 test for those plants that have TS that reference either Revision 1 or Revision 2 of

- RG 1.52, Table 5-1 of ANSI N509-1976, or ANSI N510-1975 can only be relieved by license amendment.

Cateoorization of Plants Since February 1996, the staff has issued three emergency TS changes to licensees that had determined that the tests they performed were not in compliance with their TS because the required testing standards and test protocols did not support a teet in which the temperature is changed as required by the TS. If the temperature in the test apparatus is changed from 25 *C [77 *F] to 80 *C [176 *F] during the test without modifying the test protocol, water condenses on the charcoal, thereby causing the test to be aborted (to fail). The emergency TS changes were issued for the V.C. Summer, Davis-Besse, and Oconee facilities. The details of these TS changes are discussed below. N

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On February 10,1996, the licensee for the V.C. Summer Nuclear Station, South Carolina l

Electric & Gas Company (SCE&G), requested an emergency TS change. The systems involved were the control room emergency ventilation system and the fuel handling building exhaust system. On February 10,1996, the NRC granted the emergency TS change. The emergency TS change was requested because SCE&G bad determined that laboratory tests of the charcoal of the control room ventilation system and the fuel-handling building system had not been performed in compliance with the V.C. Summer TS. The laboratory test performed for V.C. Summer was a 25 25-25 test in lieu of the 25-80-25 required by its TS. The licensee had been performing the 25-25-25 test because, in consultation with its testing laboratory, it concluded that performance of the 25-80-25 test would result in condensation on the charcoal l

and, thus, an invalid test.

On March 29,1996, the Toledo Edison Company requested an emergency TS change for the Davis-Besse plant. The systems involved were the hydrogen purge, the shield building emergency ventilation, and the control room. The TS for Davis-Besse required the laboratory test to be performed in accordance with RG 1.52, Revision 2. In this case, the licensee was performing a 30-30-30 test using the testing protocol of ASTM D3803-1979 in lieu of the 25-80-25 test. On March 29,1996, the NRC granted the emergency TS change to allow the 30-30-30 test.

On April 2,1996, Duke Power Company requested an emergency TS change for the Ocoriee Nuclear Station. The systems involved were the reactor building purge, the opent fuel pool ventilation, and the penetration room ventilation. The TS for Oconee required the laboratory test of charcoal to be performed in accordance with ANSI N510-1975 and Method C of ASTM D3803-1979, which requires the performance of the test at 130 *C (266 'F) and 95 percent RH. However, the licensee was actually performing a 30-30-30 test using the test protocol of ASTM D3803-1989. The NRC granted an emergency TS change on April 2,1996, to permit the 30-30-30 test.

In each of these cases, the test performed to demonstrate compliance with TS provided results that the staff considered closer to reflecting the capability of the charcoal than the test required by the TS. In addition, the licensees believed that using the newer standard would satisfy their TS requirement. Their bases for this belief were the limitations of the test referenced in RG 1.52, their interpretation of ANSI N509 as allowing the use of later versions of the test protocol, and some of the guidance provided by the NRC. In the case of Oconee, the test actually performed is the test that the staff believes is the appropriate one, ASTM D3803-1989.

However, because these tests had not been conducted in compliance with the plant's TS, each licensee would have had to shut down its plant or remain in a cold-shutdown mode until the test required by the TS could be successfully performed, or until the TS were amended.

On March 21,1996, Carolina Power & Light Company flew a charcoal sample from the Brunswick standby gas treatment system (SGTS) to its testing laboratory in Ohio for the performance of the 25-80-25 test to comply with the Brunswick TS before restart of an idle unit.

The Brunswick TS required that the laboratory tests be performed in accordance with Revision 1 of RG 1.52. Previously, the licensee directed its testing laboratory to perform an 80-80-80 test. To perform the 25-80-25 test, the laboratory equilibrated the charcoal to 80 'C [176 'F] before introducing the challenge gas. The licensee has not requested a TS change for Brunswick to correct the problem and is awaiting guidance from the NRC.

5-

As a result of the emergency TS changes, the staff has performed an internal survey of operating plant TS to determine whether other plants have the potential for similar problems with complianco. The survey indicated that at least one-third of operating reactor licensees may not be in compliance with their TS because they reference the flawed 25-80-25 testing protocol and may have used later versions of the standards for the laboratory tests of their nuclear-grade charcoal. On the basis of this survey, the staff established the following four groups of plants:

(1) plants in compliance with their TS that test in accordance with ASTM D3803-1989 (2) plants in compliance with their TS that test in accordance with a test protocol other than ASTM D3803-1989 (3) plants not in compliance with their TS that test in accordance with ASTM D3803-1989 (4) plants not in compliance with their TS that test in accordance with a test protocol other than ASTM D3803-1989 The licensees in Group 1 have TS that require charcoal to be tested in accordance with ASTM D3803-1989, which adequately demonstrates the capability of the charcoal. The licensees in Group 2 have TS that require charcoal to be tested in accordance with test standards other than ASTM D3803-1989. The licensees that received emergency TS changes were in Groups 3 and 4. Licensees in Groups 3 and 4 have TS that require charcoal to be tested in accordance with the 25-80-25 test.

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SAMPLE TECHNICAL SPECIFICATIONS For Plants With improved Standard Technical Specifications C.

Demonstrate for each of the ESF systems that a laboratory test of a sample of the charcoal adsorber, when obtained as described in [ Regulatory Guide 1.52, Revision 2], shows the methyl iodide penetration less than the value specified below when tested in accordance with ASTM D3803-1989 at a temperature of 30 *C [86 *F] and the relative humidity specified below.

1 ESF Ventilation System Penetration RH see note see note below below Note: The use of any standard other than ASTM D3803-1989 to test the charcoal sample may result in an overestimation of the capability of the charcoal to adsorb radiciodine. As a result, the ability of the charcoal filters to perform in a manner consistent with the licensing basis for the facility is indeterminate.

ASTM D3803-1989 is a more stringent testing standard because it does not differentiate between used and new charcoal, it has a longer equilibration period performed at a temperature of 30 *C [86 "F) and a relative humidity (RH) of 95%

(or 70% RH with humidity control), and it has more stringent tolerances that improve repeatability of the test.

Allowable, l100% - Methyl lodide Efftciency* for Charcoal Credited in Licencee's Accident Analysis)

Penetration Safety Factor When ASTM D3803-1989 is used with 30 *C [86 *F) and 95% RH (or 70% RH with humidity control) is used, the staff will accept the following:

Safety factor 2 2 for systems with or without humidity control.

Humidity control can be provided by heaters or an NRC-approved analysis that demcostrates that the air entering the charcoal will be maintained less than or equal to 70 percent RH under worst-case design-basis conditions.

This value should be the efficiency that was incorporated in the licensee's accident analysis which was reviewed and approved by the staff in a safety evaluation.

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For Plants With Older Technical Specifications Each engineered safety features (ESF) ventilation system shall be demonstrated OPERABLE:

a.

At least once per 18 months or (1) after any structural maintenance on the HEPA filter or charcoal cdsorber housings, or (2) following paintirig, fire, or chemical release in any ventilation zone communicating with the system by:

1)

Verifying, within 31 days after removal, that a laboratory test of a sample of the charcoal adsorber, when obtained in accordance with Regulatory Position C.6.b of Regulatory Guide 1.52, Revision 2, March 1978, shows the methyl iodide penetration less than [see note in preceding section titled "For Plants With improved Standard Technical Specifications"]% when tested in accordance with ASTM D3803-1989 at a temperature of 30 *C [86 *F] and a relative humidity of

[see note in preceding section titled "For Plants With improved Standard Technical Specifications"]%

b.

Within 31 days of completing 720 hours0.00833 days 0.2 hours 0.00119 weeks 2.7396e-4 months of charcoal adsorber operation, verify that a laboratory test of a sample of the charcoal adsorber, when obtained in accordance with Regulatory Position C.6.b of Regulatory Guide 1,52, Revision 2, March 1978, shows the methyl iodide penetration less than [see note in preceding section titled "For Plants With improved Standard Technical Specifications"]% when tested in accordance with ASTM D3803-1989 at a temperature of 30 *C [86 *F) and a relative humidity of [see note' in preceding section titled "For Plants With improved Standard Technical Specifications"]%

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f, ATTACHMENT 2 STAFF RESOLUTION OF PUBLIC COMMENTS RECEIVED ON DRAFT GENERIC LETTER ENTITLED

" LABORATORY TESTING OF NUCLEAR-GRADE ACTIVATED CHARCOAL" (FEDERAL REGISTER VOL. 63, No. 37 Doc. 98-4761)

The staff received 23 letters in response to the draft generic letter entitled " Laboratory Testing of Nuclear-Grade Activated Charcoal." From the 23 letters, the staff identified 130 comments.

Of these,83 were repetitive, leaving 47 distinct comments. The following discussion provides the distinct comments received and the NRC staff's response to these comments. The staff's responses state clearly whether, and how, the generic letter was revised to reflect a particular comment. Appendix A provides a list of the 23 respondents and Appendix B provides a matrix showing which comments each respondent provided.

Comment 1: (NUCON International, Inc.)

This letter does not adequately address one of the ongoing problems that we face: the specifications for testing new charcoal are different from those for testing used carbon.

Furthermore, we feel that the AG-1 code might be a more appropriate vehicle to address the charcoal testing problems (where ASTM D3803-1989 is invoked as a requirement) than the procedure of ASTM D3803-1989 alone, e.g., if the particular batch is for a system to be tested at 30 "C, 70 percent relative humidity (RH), would the new carbon be tes:ed at 70 percent RH or 95 percent RH orboth? Who wouldspecify the choices? Current specifications fornew carbon require ' qualification

and ' surveillance" tests. The NRC letter discusses only surveillance testing. What is the impact on currently required " qualification' tests? '

Resoonse:

The proposed generic letter addresses surveillance testing requirements for used charcoal. It was not intended to cover new charcoal qualification testing issues. The staff has determined that it would be more appropriate to incorporate the qualification testing comments in the next revision of Regulatory Guide 1.52.

Comment 2: (NUCON Intemational, Inc.)

The explanation for the increase in iodine removal efficiencies at higher temperatures (discussed on page 9583 of the Federal Reaister notice) does not take into consideration the increased reaction rate that occurs as the temperature is increased, which is the cause of the increased iodine removal etficiencies.

Response

The staff has revised the generic letter to more clearly explain that the iodine removal efficiency of the charcoal increases at higher temperatures because of the increased reaction l

rate at higher temperatures.

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E Comment 3:. (Similar comments appeared in 14 individual letters)

The actions proposed by NRC could not be met within the proposed schedule. If adopted as 1

proposed, the generic letter will require licensees to perform charcoal testing within 60 days of the date of the letter and to submit a revised technicalspecification to the NRC which invokes i

ASTM D3803-1989 as the testprotocol, as required. As statedin the generic letter, only two commerciallaboratories, NUCON and NCS Corporation, are available to perform such testing.

If problems are encountered, the need to replace charcoal could overburden charcoal suppliers with multiple requests forchar00el. This willbe in addrtsor to the normaltesting burden on the existing laboratories. Replacement of any activated charcoaladsorbers requires in-place bypass testing in accordance with Regulatory Position C.5.d of Regulatory Guide 1.52, Rev. 2.

For many licensees, this requires field support from the same two companies that perform the laboratory testing. This willbe an addWonalstrain on existing resources. Sixty days is insufficient time to withdraw sample trays, ship them to test labs, perform testing, fabricate or I

refill trays where needed, conduct receipt inspections, install new charcoal, conduct in-place testing, and retum filter systems to service. Logistically, it will be impracticalif not impossible

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for the hcensees and the laboratories to meet the 60-day time frame imposed by the generic I

letter. It would be a more reasonable emectation to have each plantperform testing (i.e.,

ASTM D3803-1989 or other utility proposed testing) at the next scheduled charcoal sampling test date or within 100 days (orpreferably one fuel cycle) of the date of the generic letter. A 180-day testing schedule is consistent with the safety significance of this issue. In addition, the proposed generic letter states that "the staff believes that most charcoalin use is not degraded to an extent that would adversely affect control room haNtability orpublic health and safety.*

Providing a 180-day time frame for testing would allow sufficient time to implement the appropriate testingprotocol. It shouldbe noted that filter applications that are normally inaccessible during plant operation may require a unit shutdown in order for the testing to be performed. Further, the development of an attemate testprotocol within 60 days as propo&&d by the generic letter would be virtually impossible. ' The time required to collect and evaluate the

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i information necessary to address the 13 points requiredby the NRC to determine the acceptabiHty of an attemate protocol wouldbe much greater than the 60 days proposedin the

. generic letter. For sites that have submitted the improved Technical Speci6 cations (ITS) for i

NRC review, licensees should be aNowed to incorporate the changes into their ITS, rather than

.'revssing theircurrent TechnicalSpecris0ations. The emendedimplementation periodis necessary to allow for testing laboratory backlog, charcoal availability forprocurement and

'attemate train testing for the same system.

Besoonse:

The staff has revised the generic letter to request licensees in Groups 2,3, and 4 to test their charcoal at the next required laboratory surveillance test of a charcoal sample that is 60 or more days after the date of this generic letter. It is not the intent of this generic letter to cause plants to shut down. Therefore, if a plant must shut down to perform this testing, the licensee may seek relief from the time limits for testing specified in the generic letter (see response to Comment 24). If a plant has submitted the iTS and the ITS is scheduled to be completed within a year from the issue date of the generic letter, then the licensee may seek relief from the time limits for submittal of a technical specification amendment as specified in the generic letter. If a licensee has a specific problem that is not addressed by the generic letter, then the licensee may seek relief from the time limits specified in the generic letter.

I

'2 u

Comment 4: (Similar comments appeared in 4 individual letters)

The lastparagraph of " Requested information' states that 'the independent laboratory should 1

not be engaged in the measurement ofiodine penetration of charcoal as a business either for TS compliance purposes or for the sale andtorprm*w+nn of activated charcoal for nuclear powerplant applications

While it is obvious that this requirement is to prevent a conflict of

. Interest, it also increases the burden of finding an acceptable independent lab that is capable of performing the required tests andproviding adequate quality assurance. The laboratories that currentlyperform testing to the ASTM standard should not be excluded from performing the

. quencation testing fornew, prqposed testprotocols. These laboratories have extensive i

emedence in testing nuclear grade charcoal, have established quality assurance programs, -

and have the equipment and facilities to safelyperform this testing. In addition, the extensive emerience that these laboratories have gained byperforming testing to the ASTM standard provides added assurance that the prqposed test protocol will be evaluated accurately and objectneely. By restricting the use of existing laboratories for test development, the altomate test pavivcol cannot be completed without setting up a new laboratory, which is cost prohibitive.

if an attemnte testprotocolis proposed, the utility should be allowed access to the existing i

testinglaboratories.

1

Response

i The staff has revised the generic letter to require the use of at least two laboratories in determining the acceptability of the attemate protocol One laboratory should be used to develop the attemate protocol and the other to demonstrate the repeatability and reproducibility -

of the altemate protocol. The two laboratories should be able to demonstrate that the altemate protocol is at least as conservative as ASTM D3803-1989, and should be able to perform the ASTM D3803-1989 test and achieve repeatable and reproducible results.

Comment 5: (NUCON Intemational, Inc.)

. As discussed on page 9585 of the Federal Regtster notice, the face velocity requirement in Requested Information items 2 and 3 would also apply to syster.,s that are more than 10 percent below 0.203 m/s [40 ft/ min) as well.

Response

'The staff is mainly concemed with systems that have an as-built face velocity greater than the face velocity used to perform the laboratory charcoal sample test. The laboratory test will overestimate the capability of the charcoal when the charcoal is tested with a face velocity that is less than the face velocity to which the charcoal is actually exposed when installed in the system. This happens because as the velocity of the contaminated air passing through the charcoal filter is reduced, the amount of time (called residence time) the air is in contact with the charcoal increases, thus increasing the adsorption. Therefore, the staff did not revise the generic letter to specify 40 fpm

10 percent.

3

. Comment 65 (Similar comments appeared in 2 individual letters)

On page 9586 of the Federal Reaister notice, the statement is made that the ASTM D3803-1989 standard has two additional testing periods that are not required by other standards. The statement is also made that during the stabilization period, air at the test temperature is passed through the charcoal beds. This is not correct. During the stabilization period, the carbon is brought to thermal equilibrium with the test temperature. The erroneous Federal Register statement could be misinterpreted and should be revised to agree with Sectron 12.1 of ASTM D3803-1969. The duration of this stabilization periodis recommended to

^ be a minimum of 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months , during which the canisters and the carbon must come to thermal

,_ equilibrium at the spectfred test temperature.

Response

The staff has revised the generic letter to correctly specify that during the stabilization period the carbon is brough* ' thermal equilibrium with the test temperature to agree with Section

.12.1 of ASTM D3803-1989. In addition, the generic letter has been revised to specify that the

' duration of this stabilization period is recommended to be a minimum of 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months , during which L the canisters and the carbon must come to thermal equilibrium at the specified test temperature.

Comment 7: (Similar comments appeared in 2 individual letters)

On page 9687 of the Federal reaister notice, the statement is made that charcoal retains about 40 weight percent water at 30 *C and 95 percent RH and 2m3 weight percent at 80 *C and 95 percent RH. These values are incorrect. Typically 24-25 weightpercent wateris adsorbed at 30 *C and 95 percent RH (see ASTM D3803-19R9 A5 and Figure 1, EGG-CS-7653);

experience in ourlab has shown that 19m20 weightpercent wateris adsorbed at 80 *C and 95 percent RH. This amount of wateris nearly equivalent to the amount adsorbed at 30 *C and 70 percent RH and probably explains in large part why the methyllodide efficiency is typically 99.9 percent for both the 30/70 and 8095 (again see ASTM D3803-1989 A5 and Figure 1, EGG-CS-7653).

Response

The staff has revised the generic letter to correctly specify that charcoal retains about 24-25 weight percent water at 30 *C and 95 percent RH and 19-20 weight percent water at 80 *C and

. 95 percent RH.

Comment 8: (NUCON Intemational, Inc.)

On page 9587 of the Federal Reaister notice, the statement is made that the longer equilbration time is ropa sentative of the conditions " expected during design base conditions;'

this is not correct in terms of the purpose of ASTM D3803-1989. This methodis sensitive to the condition of the charcoal for radioactive methyliodide removal but is not necessarily related to expected ccediticms.

4

Response

The staff has revised the generic letter to correctly specify that the longer pre-equilibration time is more conservative because it will completely saturate the representative charcoal sample which ensures reproducibility of the results by having every charcoal sample begin the test at the same initial conditions.

Comment 9: (Similar comments appeared in 5 individual letters)

The approach taken in the proposedgenericletteris a very conservative *one size fits all' approach without a thorough evaluation of the plant-specifoc design-basis. Performance of this testing, while conservative, may exceed, ornot be representative of, the design basis for various Miter applications. The draft generic letter would require filter testing at 30 *C according to the ASTM D3803-1989 protocol. These conditions wouldbe viewedas generally representative of conditions for filters located outside of containment. On the basis of expected accident conditions, filter units locatedinside containment would be expected to operate at temperatures on the order of 130 *C when required to be in service. Accordingly, ASTM D3803-1989, when performed at 30 *C, is not representative of design operating conditions inside containment. The proposed test would be overconservative compared to a test at higher temperatures representative of conditions inside containment. On the basis of the foregoing, the scope of a finalgeneric letter should, therefore, be restricted to outside containment applications only.

Response

TMI Action item lil.D.3.4, " Control Room Habitability," required that licensees analyze all design-basis accidents with regard to control room operator doses (GDC 19). A temperature of 30 *C is more appropriato than 130 *C for design-basis accidents such as a fuel handling accident inside containment. Therefore, testing the charcoal samples at 30 *C is bounding for all design-basis accident conditions. The staff has determined that if credit is taken for the containment recirculation charcoal filters in the plant's design-basis dose analysis, the charcoal should be tested in accordance with ASTM D3803-1989. ASTM D3803-1989 is the only available test that (1) provides a reproducible standard test method for determining the quality of the charcoal and (2) provides the ability to adequately discriminate between good and bad charcoal. If the containment recirculation charcoal filters are not needed to meet

' 10 CFR Part 100 and GDC 19 dose limits, the licensee can, if it desires, provide the staff with a revised dose analysis without taking credit for the coritainment recirculation charcoal filters.

The staff has previously approved this for several plants. The staff has revised the generic letter to state that if a licensee chooses to test its charcoal samples at actual accident conditions which are different from the test conditions specified in ASTM D3803-1989, then that test shnuld be treated as an attemate protocol.

Comment 10:. (Similar comments appeared in 2 individual letters)

On page 9585 of the Federal Reaisternotice, RequestedInformation item 2, the statementis made that plants adopting the ASTM D3803-1989 protocol are required to submit certain information regarding testparameters to supp:%1 a TS amendment. In adopting the ASTM D3803-1989 protocol, certain conditions of the protocol are accepted as variables by the 5

~ ~ ~ - - ^ ^ - ^ - ^ "

Commission. While the Commission is correct in requiring information on test parameters that may vary from plant to plant, e.g., relative humidity and face velocity, requesting the test temperature implies that this parameteris also a variable, which it is not. The test temperature

~ of 30 *Cis the only acceptable temperature. In order for the Commission to fully evaluate TS amendment requests, we believe the variable of test bed thickness should be includedin the list

' of requestedinformation since bed thickness affects gas residence time in the bed as does face velocity. The penetration at which the proposed TS willrequire the test to be performed should spectfy the actual bed thickness for which credit is taken.

Response

The proposed generic letter requests the test temperature because Annex A5 of

- ASTM D3803-1989 states that nuclear facilities that have different operating conditions may use a test temperature other than 30 *C. Therefore. the staff has determined that it is necessary to specify a temperature of 30 *C because test temperatures other than 30 *C are not acceptable. Regarding the test bed thickness, the staff has revised the generic letter to request the charcoal bed thickness.

Comment 11:. (Similar comments appeared in 2 individual letters)

On pages 9588 and 9589 of the Federal Reposter notice (" Sample Technical Specifications"),

the statement is made that when referring to ASTM D3803-1989 and the required test relative humidity and temperature, the term greater than or equal to and the symbol for less than or equal to are used. A temperature of 30 *C and relative humidity of 95 percent or 70 percent shouldbe specthed without the use of this symbol or term. Allowing changes in test temperature and humidity, abeit in a conservative direction, etfectively changes the method andis contrary to NRC/INEL decolopmental work.

Response

~

The staff has revised the sample technical specifications in the generic letter to remove the

" greater than or equal to" and "less than or equal to" terms and to just state "at a temperature of 30 *C and a relative humidity of 95 percent (or 70 percent with humidity control)."

Comment 12: (Similar comments appeared in 4 individual letters)

An oral request for an extension of the public comment period to better understand and respond to the complexities of this issue was denied by the NRC staff. This short comment

- period has hindered the ability of the industry to fully explore the merits of the technical proposals in the proposed generic letter. We recommend that Mure public comment periods be a minimum of 45 days, consistent with the safety significance and resource impact of the issue.

.I i

d mihm i i iiiimmi

Response

The 30-day public comment period for this generic letter is commensurate with the staff's policy (Section 6.25 of Generic Communications Branch Procedure No.1, Revision 1," Processing of Proposed Generic Communications") regarding the length of the public comment period for generic letters and is therefore adequate for this proposed generic letter. However, comments received by the staff as late as 90 days after the proposed generic letter was published in the Federal Reaister for public comment were considered.

j Comment 13: (Similar comments appeared in 11 individual letters)

We believe the regulatoryprocess was not followed properly. The proposed new generic requirement and staff position has not beenjustified by an appropriate regulatory analysis.

l The Federal Reaister backfit discussion characterizes the requested actions as necessary to i

demonstrate compliance. In examining the issues involved, we conclude this is an incorrect application of the compliance exception provision of the Backfitting Rule,10 CFR 50-109.

Paragraph (a)(1) of f50.109 states that '[b]ackfitting is defined as the modification of or addition to systems, structures, components... or the procedures... required to design, constivct or operate a facility; any of which may result from a new or amendedprovision in the Commission rules or the imoosition of a reaulator staff oosition interoretina the Commission rule that is either new or different from a orevious aoolicable staff oosition..."

[ underline added for emphasis].

The NRC previously established 'a regulatory staff position interpreting the Commission rule' when it approved licensee test methods documented in plant technical specifications or accepted otherlicensee commitments. These approved test methods were deemed by the NRC at the time to be in compliance with the regulatory requirements citedin the proposed generic letter. In accordance with 10 CFR 50.109(a)(3), the NRC staff must demonstrate a significant safety improvement relative to the costs to be incurred by licensees before imposing the improved ASTM testmethod.

Response

The NRC has decided that the generic letter is a backfit, but the Section 50.109(a)(3) finding need not be demonstrated in a backfit analysis because the NRC considers the generic letter to be a compliance backfit pursuant to Section 50.109(a)(4)(i). The staff's position is that the licensees are required to demonstrate compliance with the dose limits of GDC 19 of Appendix A to 10 CFR Part 50 as incorporated in their licensing basis either during initial plant licensing or as a result of TMI Action item Ill.D.3.4. The staff identified as early as 1987 (Information Notice 87 32) that problems existed with charcoal laboratory testing methods used to demonstrate compliance with the dose limits of GDC 19 and Part 100. The proposed generic letter provides additional evidence that existing test protocols other than ASTM D3803-1989 do not provide accurate and reproducible test results and therefore do not ensure compliance with the dose limits of GDC 19 and Part 100.

7

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i Comment 14: (Similar comments appeared in 5 individual letters)

J The proposed generic letter identifies that ' based on the available laboratory test results, the staff believes that most charcoalin use is not degraded to an extent that would adversely affect control room habitability orpublic health and safety.' Since the result of the proposed change in testing methodology is not expected to uncover that the currently installed systems would not be able to perform their design function, the revised testing methodologyis not required for compliance with 10 CFR 100 or GDC 19, nor is it expected to result in a significant safety benefit.

Response

The quoted paragraph states that "most" charcoal is not degraded. However, on the basis of available laboratory test results, the staff also believes that there are a group of plants with

. degraded charcoal and the required test in their technical specifications is ineffective in identifying the degradation. As a result, these plants are not in compliance with 10 CFR Part 100 or GDC 19 dose limits. Although the staff believes today that most charcoal is not significantly degraded, it is essential to use reliable and reproducible test standards to identify future degradation of the charcoal. Therefore, this generic letter is necessary.

Comment 15: (Similar comments appeared in 5 individual letters)

The purpose of crediting charcoalin the licensing basis is to filter volatile forms oflodine (i.e.,

elementaland organic). Current Regulatory Guides 1.3 and 1.4 assume 95 percent oflodine to be this type.' NUREG-1465 stated that where pH is controlled at values of 7 orgreater within the containment, elementaliodine can be taken as comprising no more than 5 percent of the tota

lodine released, and lodine in organic form may be take as comprising no greater than 0.15 percent of the totaliodine released. Thus, the elementaland orgenic lodine releases are over an order of magnitude less than those obtained with the existing !!=ensing source tenn.

This greatly reduces the safety signihcance of charcoal filtration.

Operating plants (i.e., pilot plants) have submitted revised source term analyses to NRC that meet done limits with no credet for charcoalfiltration. In addition to the operating plant analyses, NRC has certofred the System 80+ Advanced Light Water Reactor (ALWR) with no credit for the charcoalfilters in the annulus filtration system. On the basis of the NUREG-1465information and these operatingplant and ALWR applications, TVA notes that requirements for additional charcoal testing are unlikely to have any safety significance. Consequently, the need for this genericletteris not clear.

Response

Revised (NUREG-1465) source tenn rebaselining efforts are almost complete. The combination of the revised chemical form of the source term in NUREG-1465 and the proposed

. change in the dose limits (TEDE) deemphasizes the importance of charcoal filtration. The results from the revised source term rebaselining seem to indicate that for some plants that

~ dopt the NUREG-1465 source term and the TEDE dose limits, charcoal filtration may not be a

necessary, but this would need to be reviewed on a case 4y-case basis. Although the chemical form of iodine distribution has changed, the major component of the release from containment remains organic efter sprays, suppression pools, and ice condensers have performed their 8

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function. Therefore, if charcoal adsorption is required to meet the dose limits, then it is important to adequately test the charcoal because organic will be the form to remove. In addition, for certain accidents which are not impacted by the revised source term (e.g. fuel handling accident, main steam line break, and steam generator tube rupture) the chemical forms to be released are principally organic which may need to be adsorbed by the charcoal in the control room emergency ventilation system and the fuel handling building ventilation system to meet the dose limits. Also, for plants that continue to use the TID-14844 source term, charcoal in ESF filtration systems will still be needed to meet the dose limits of GDC 19 and

.Part 100.

Comment 16:. (Similar comments appeared in 4 Individual letters)

. As statedin the proposed genericletter, many of the currentproblems occurred as the result of i

' 'conRicting guidance" and " complex and ambiguous' standards. Therefore WPSC strongly encourages the staff to revise Regulatory Guide t.52, the Standard Review Plan, HPPOS-069, and NUREG-1431 before itissues the prop 0&&Jgenericletter. Revising the guidelines first will provsde licensees with clear and consistent guidance.

Response

As required by the Staff Requirements Memorandum dated February 5,1998, the staff has developed plans to expedite its revision of the regulatory guidance applicable to the testing of safety-related charcoal. This work will not be completed before the generic letter is issued because laboratory testing of charcoal filters is only a small portion of the changes that need to 1

be made to the regulatory guidance. However, NUREGs 1430-1434 will be revised following the issuance of the generic letter to reflect the sample technical specification that appears in of the genericletter.

Comment 17: (Entergy Operations,Inc.)

~

The lessons loamed from the regulatory box that the NRC describes (e.g., the utilities being prevented from using improved testing methods) should be addressed in a more comprehensive manner thanjust addressing this isolatedissue As thscussedin the proposed generic letter, the NRC requires licensees to spell out the spe:ish trethods of filter testing in their Technical Spectfocations. The spectroc methods forperforming surveillances are not generally containedin the TechnicalSpectfscations. Theinclusion of the detailedrequirements for filter testing places excessive burdens on licensees and the NRC staff and should be removed to allow licensees to apply improved methods.

Response

i As a result of the past and present confusion regarding appropnate laboratory testing i

requirements, the staff has determined that the detailed requirements for charcoal filter testing need to be included in the technical specifications to clarify what the NRC staff has found acceptable. For plants converting to the improved standard technical specifications (ITS), the i

charcoal laboratory testing requirements are in the Administrative Section of the ITS as part of the ventilation filter testing program rather than being provided as a specific surveillance requirement as in older technical specifications. By moving these and other testing 9

t

requirements to the Administrative Section of the ITS, the staff has significantly reduced the amount of specific methods provided in the Surveillance Section.

In light of the lessons leamed from the charcoal fi!ter testing issue, the NRC staff has been sensitized to and will focus on other generic testing issues.

Comment 18: (Similar comments appeared in 5 individual letters)

To improve the efficiency of the regulatoryprocess, licensees and NRC should assess the issues highlighted in the prqposed generic letterin concert with the relatedissues of control room habitability, other emergency ventilation systems, and revised source term insights.

Because this issue has low safety significance, and because of the lack of evidence that those licensees using chercoal test standards other than the ASTM D3803-1989 standard are not in compirance, further dialogue is appropriate before finalizing any generic request for information.

We recommend that a joint NRC-industry workshop be conducted. This wouldpermit a more comprehensive descussion of NRC andindustry concems as they relate to charcoa!lest methodologies, control room habrtability, other emergency ventilation systems, and appilcation of the revised source term. Any new NRC staff guidance orpositens should only be established alter an integration of the relevant technical test performance and risk insights.

Response

e-The staff met with representatives from NEl and NHUG on May 7,1998, to discuss this public comment and it was decided that a specific workshop conceming charcoal filter testing would not be the most efficient use of industry and NRC resources. However, it was decided that the generic letter would be discussed at the NRC/NEl/NHUG Workshop on Control Room Habitability on July 16,1998, at the 25th DOE /NRC Nuclear Air Cleaning and Treatment Conference on August 3-6,1998, and at the Summer '98 NHUG Conference on August 6-7,1998.

Comment 19: (Arizona Public Service Company)

The third bullet of paragraph 9 of ' Discussion

requires licensees to submit an amendment.

request to their technical specrHcations. Implied in this bullet is that licensees are required to amend their technicalspecifwations to reference ASTM D3803-1989. Clarification shouldbe

. provided to state that this amendment request may propose an attemative test protocol.

Response

The staff has revised the third bullet of paragraph 9 of the " Discussion" section of the generic

. letter to clarify that the amendment request may propose an altemate test protocol.

Comment 20: (Similar comments appeared in 2 individual letters)

I We believe the generic letter shouldinclude a statement in all sections indicating that the

- ASTM D3803-1989 testing can be performed at 70 percent RH in lieu of 95 percent RH if the

. design bases of the ESFsystem includes humidity controlin the form of duct heaters or design y

Y

'10

analysisjustification that the airis maintainedless than or equal to 70 percent RH without the use of duct heaters.

Resoonse:

The staff has revised Enclosure 2 of the generic letter to clarify its position on humidity control.

The staff's position is that plants whose design basis includes an NRC-approved analysis that demonstrates that the air entering the charcoal is maintained at less than or equal to 70 percent RH without the use of heaters and under worst-case design-basis conditions can test their charcoal at 70 percent RH.

Comment 21: (Arizona Public Service Company)

Paragraph 7 of " Discussion

states that the staff has previously approved reductions in the safety factor forplants adopting ASTM D3803-1989 on a case-by-case basis. Generic guidance should be provided that outlines the NRC-accepted criteria used to allow reductions in the safety factor so that facilities may implement the reduced safety factor, if appropriate, without having to obtain prior NRC approval.

Resoonse:

j The use of the safety factor is discussed in paragraph 7 of the " Discussion" section as well as in j

the sample technical specification note provided in Enclosure 2. However, prior NRC approval is still required. The staff has revised the generic letter to clarify the appropriate use of the

,j safety factor by providing a reference in paragraph 7 of the " Discussion" section to the sample technical specification note provided in Enclosure 2.

Comment 22: (Southern Califomia Edison)

The generic letter should include more detailin all sections on how to apply the safety factor of 2 for determining the acceptance criteria for charcoal removal efficiency. For example, if the licensee's design removal efficiencyis 95 percent as specifiedin Table 2 of Regulatory Guide 1.52, Revision 2,1978, and ASTM D3803-1989 is used forlaboratory testing of charcoal, the acceptance criteria can be 97.5 percent. This acceptance criterion can be calculated as follows:

Acceptance Criterion = Design Bases Removal Efficiency (DBRE) + (100 - DBRE)/ SF

= 95 + (100 - 95)/2.0

= 95 + 2.5

= 97. 5 percent (SF= Safety Factor = 2.0)

Response

The use of the safety factor is discussed in paragraph 7 of the " Discussion" section as well as in

. the sample technical specification note provided in Enclosure 2. In addition, the formula for calculating the acceptance criterion appears in the sample technical specification note in 11

.. The staff has revised the generic letter to clarify the appropriate use of the safety factor by referring in paragraph 7 of the "Discuscion" section to the sample technical specification note in Enclosure 2.

Comment 23: (Virginia Power)

The prop 0&&d generic letterindicates that ASTM D3803-1989 is the test method of choice.

This test uses methyllodide to test the charcoal adsorbers for efficiency in removing orgenic iodine. Basing acceptance criteria on methyliodide retention may not ensure comp.'iance with existing accident analyses where inorganic (elemental) iodine retention in adsorbers is the limiting factor. Depending on plant design, some accident analyses assume higher elemental lodine removal filter efficiency than that of organic iodine. In otheraccident analysis cases, only elementallodine filtration is credited. Using the ASTM D3803-1989 testing methodology has an implicit assumption that organic lodine is the controlling element and that elementaliodine is removed at a higher rate than organic iodine. This may not be applicable to allplants. On the basis of descussions with vendors, test laboratories, and our review of the existing test data, we do not believe that it is possible to draw a correlation between organic andinorganic retention for all retention percentages which are containedin current accident analyses. ASTM D3803-1989 does not evaluate the removal efficiency for elementaliodine. Therefore, we believe that an attemate test may be required to determine the removal efficiency for elemental iodine.

Response

{

Particulate and elemental forms of iodine are anticipated to be aggressively removed through the use of sprays, suppression pools, ice condensers, and spent fuel pool water. Therefore, the form of iodine that is anticipated to require treatment by ESF filtration systems is organic.

The staff has determined that all charcoal should be tested in accordance with ASTM D3803-1989 because it is the only available test that (1) provides a reproducible standard test method for determining the quality of the charcoal and (2) provides the ability to adequately discriminate between good and bad charcoal. ASTM D3803-1989 is a very stringent and reliable measure of the ability of charcoal to fulfill its intended purpose, i.e., to remove radioiodine in any chemical form from air within a nuclear power plant. The specified

' test conditions cannot cover the diverse conditions encountered by the variety of charcoal applications within power plants under normal and emergency operations. Attempts to predict charcoal performance based on simulations of the myriad number of hypothesized accident conditions have only lead to chaos for both the test specifications and the regulatory acceptance criteria employed. This confused situation has led to enormous inequities for the nuclear power industry by allowing some plants to retain seriously degraded or " spent" charcoal while requiring others to replace acceptably good charcoal frequently. To remedy this situation, licensees should adopt the ASTM D3803-1989 standard test method.

Comment 24: (Siniilar comments appeared in 6 individual letters)

. Calvert Cliffs currently tests all of the nuclear-grade activated charcoal used outside of the containment buildings in accordance with ASTM D3803-1989, and our Technical Specifications

. reference ASTM D3803-1989. We test the nuclear-grade activated charcoal used in the containment iodine filter trains in accordance with the same ASTM, with exceptions for 12

l I

e I temperature, species ofiodine, andpressure to more closely reflect the actualpost-accident conditions in our containment buildings. Testing the containment iodine filter trains using the temperatures, pressures, and species ofiodine as required by the ASTM D3803-1989, without exceptions, would require Calvert Cliffs to replace the charcoal currentlyin the lodine filters at a cost of approximately $300,000 for all six filters. The replacement of the charcoal also requires

\\

that the unit be offline and shut down, creating substantiallost revenues. We feel that none of these actions create a commensurate increase in the health and safety of the public. Calvert Cliffs and similarly designed plants should not be subject to the proposed generic letter.

Response

The staff has determined that if' credit is taken for the containment recirculation charcoal filters 1

in the plant's design-basis dose analysis, the charcoal should then be tested in accordance with ASTM D3803-1989. ASTM D3803-1989 is the only available test that (1) provides a reproducible standard test method for determining the quality of the charcoal and (2) provides the ability to adequately discriminate between good and bad charcoal. If the containment recirculation charcoal filters are not needed to meet 10 CFR Part 100 and GDC 19 dose limits,

~I then the licensee should give the staff a revised dose analysis without taking credit for the containment recirculation charcoal filters. The staff has previously approved this for several plants and will entertain such a request in response to this generic letter.

It is not the intent of this generic letter to cause plants to shut down. Therefore, if a plant must shut down to perform this testing, then the licensee may seek relief from the time limits for testing specified in the generic letter (see response to Comment 3).

Comment 25: (Similar comments appeared in 5 individual letters)

The proposed generic letter identifies several actions the NRC expects licensees to undertake to increase confidence that they comply with theirplant's licensing bases relating to the dose limits of General Design Criterion (GDC) 19 of10 CFR Part 50 Appendix A and 10 CFR Part 100, Subpart A. These actions include changes to plant Technical Spectfocations and testing of charcoal samples in accordance with American Society for Testing and Materials (ASTM)

D3803-1989, " Standard Test Method for Nuclear-Grade Activated Carbon.' The role of a generic letteris to gather or disseminate information, not to impose new requirements.

Therefore, the proposalis an inappropriate use of the generic letterprocess. It should not be issued until comments are carefully considered and resolved.

Response

NRC Inspechon Manual Chapter 0720, "NRC Generic Communications Regarding Nuclear lasues," specifies that a generic letter is a type of generic communication that

1. Requests that analyses be performed or descriptions of proposed corrective actions be submitted regarding matters of safety, safeguards, or environmental significance. The licensees may be asked to accomplish the actions and report their completion by letter with or without prior NRC approval of the action. Information relating to these analyses may be requested on a voluntary basis or in accordance with Section 182a, Atomic

Energy Act of 1954, as amended, and 10 CFR 50.54(f). Usually, this type of generic letter 13

requests new or revised licensee commitments or other continuing actions, but may not explicitly or coercively solicit licensee commitments.

- The proposed generic letter requests that licensees test their charcoal in accordance with a different test standard (ASTM D3803-1989) than the one currently specified in their technical specifications.

2. Requests lic'ensees to submit technical information which NRC needs to perform its function. The information may be requested on a voluntary basis or in accordance with Section 182a, Atomic Energy Act of 1954 as amended, and 10 CFR 50.54(f).

- The proposed generic letter requests that licensees submit specific laboratory test

. parameter information.

3. Requests or provides the opportunity to licensees to submit proposed changes to technical specifications.

- The proposed generic letter requests that licensees submit a technical specification

. amendment requiring testing of charcoal in accordance with the ASTM D3803-1989 standard or propose an altemate test protocol.

4. Provides staff technical or policy positions not previously communicated or broadly I

understood.

- The proposed generic letter reiterates the staff position that testing charcoal to the previous, NRC-endorsed ASTM D3803-1979 standard does not provide the needed assurance that licensees are complying with their respective, plant licensing bases as they relate to the dose limits of General Design Criterion 19 of Appendix A to 10 CFR Part 50, and Subpart A of 10 CFR Part 100. This information was previously conveyed to licensees in Information Notice 87-32. The proposed generic letter -

endorses ASTM D3803-1989 as an acceptable charcoal testing protocol for verifying compliance with plant licensing bases.

Therefore, the staff has determined that the proposed generic letter is an appropriate use of the generic letter process.

Comment 26: (Nuclear EnergyInstitute)

The draft generic letter permits licensees to propose altemate test protocols for laboratory testing of charcoalin lieu of using the ASTM D3803-1989 standard. But, the NRC staff guidance is that any attemate protocolis to be compared to ASTM D3803-1989. The evaluation of an attemate test method should be based on its ability to assure that the licensing besos is satisfied, which is not necessarily the same performance criterion as that contained in i

the 1989 standard.

4

Response

14 i

i

R*

u a.

If a licensee proposes an attemate test protocol, then the NRC staff expects that the attemate test protocol be subjected to the same rigorous program that was essenual in the development of ASTM D3803-1989 (see response to Comment 4).

Comment 27: (Similar comments appeared in 4 individual letters)

The staff cites test results showing that testing to ASTM D3803-1989 produces more accurate inessures of charcoalperfonnance. Requiring utilities to submit test results has no value since l

NRC has already reached a determination about the unsuitability of testing to earlier test

- standards. The requirement to supply test results showing the charcoalis tested to the

' ASTM D3803-1989 standard shouldbe deleted. This would reduce the burden of the generic information request wtthout reducing the level ofprotection afforded the public.- Additionally, if

. filter systems have been recently filled with new charcoal that was tested to the 1989 standard

{;

by the manufacturer, additional testing and submission of results should not be required. See ^

RequestedAction 2(i).

Where licensees have tested to ASTM D3803-1989, the results are either satisfactory or the i charcoalis eplaced with new charcoal which has passed ASTM D38031989 tests. Requiring submittal of test results is an unnecessary expense that shouldbe deleted. Submittalof test results should only be required where the licensee picposes an attemative to NRC-approved.

test methods (ASTMD3803-1989).

Responag:

l The staff has revised the generic letter to not require licensees to provide test results.

Additional testing will not be required because testing will be performed at the next required -

l laboratory surveillance test. (See response to Comment 3.)

Comment 28: (Similar comments appeared in 3 individual letters)

' The Paper Reduction Act Statement estimates the public reporting burden for this mandatory

' information coIIectron to be 40 hours4.62963e-4 days 0.0111 hours 6.613757e-5 weeks 1.522e-5 months per response. The generic letter does not provide the basis for this conclusion. A more accurate estimate of the burden to perform the actions i

requestedis on the order of 100 to 400 man-hours per response.

l.

Response

The staff has revised the generic letter to clarify that the public reporting burden for this mandatory information collection is 250 hours0.00289 days 0.0694 hours 4.133598e-4 weeks 9.5125e-5 months per response.

Comment 29: (Nuclear Energy Institute)

Federal Regrster notice, page 9588, fourth paragraph states that ANSI N510-1975, requires performance of the 25-80-25 test. This test is not a requirement of ANSI N510-1975.

['

Section 13.3 of the ANSI standards requires test of adsorbent samples to be performedin

'accordance with Table 4 of RDTM 16-1T, " Gas-Phase Adsorbents for Trapping Radioactive lodine Compounds.' The October 1973 edition of the RDTstandardis listedin the references

~ section of the ANSIstandard. Table 4 of the RDTdoes not specifyperformance of the 80 *C 15 L

L

test. OnlytestsforeitherI,ormethyliodidepe f 25-80-25 test is requiredby the 1976 edition of ASTM Nr ormedat 13 Guide 1.52.

509-76andRevision 1 ofRegulatory

Response

The staff has revised Enclosure 1 of the generic lette t and Method C of ASTM D3803-1979, which requires 130 *C (266 *F) and 95 percent RH.

n accordance with ANSI N510-1975 performance of the test at Comment 30:

(Similar comments appeared in 4 Individual letters)

Omaha Public Power District (OPPD), as the licensee f comments on this issue providedby the Nuclear Energy Ior Fort Calhoun March 27 1098. In addition, OPPD estimates the cnstitute (NEI)in aletterdated thepropos, ed GL atapproximately$1000000 Thi ost of Fort Calhoun Station compliance with do not seemjustifiable under the Backfitting Rule s and the costs incurred by other licensees Besconse:

Whether licensees test their charcoalin accordance with current techncial specifications or with ASTM D38031989 the test standa performing the test.- However, charcoal that can no longe ere is no difference in the cost of operators during an accident will have to be replaced with r protect the public or the control room staff does not believe that charcoal will have to be changed new charcoal, as it should be. The testing in accordance with the more stringent and standard because of the reduction of the safety factor pro out more fr actions requested in the proposed generic letter are con idreprod posedin the generic letter. The provisions of 10 CFR 50.109 in order to ensure complia s ered compliance backfits under the resolution of TMI Action Plan item lil.D.3.4. In accorda nce with the plant's licensing basis as it

, ncluding commitment to the 10 CFR 50.109(a)(4)(i regarding compliance backfit Most of Fort Calhoun's), expense stems from the cont is, a full b ce with the provisions of Comment 24 regarding possible removal of containm a nment recirculation systems. See ent recirculation systems.

Comment 31:

(Similar comments appeared in 2 individual letters)

New York Power Authority stated that "the backfit dis concludes that because the NRCissuedorders confirmicussion

)

controlroom ventilation systems, alllicensees are required t

\\

nglicensees' commitments to modify GDC 19. The accuracyof this statement cannot b

\\

o meet the dose requirements of Absent an explicit commitment and confirmatoryreview

\\

- 737, TMI Action Plan item III.D.3.4.

permits issued before May 21, 1971 (like Indian Point 3 (see NRCmemorandum, S. J. Chilk to J M Taylorders to the contrar andFitzPatrick)arepre-GDCplants SECY-92-233, " Resolution of Deviations Identified D i or, September 18,1992, regarding urng the Systematic Evaluation 16

Program")." However, Duquesne Ught Co. stated that "we agree that GDC 19 is a regulatory requirement for alllicensees."

Response

TMI Action item Ill.D.3.4,i" Control Room Habitability," required that all plants meet the dose limits of GDC 19 of Appendix A to 10 CFR Part 50. Confirmatory orders were issued to licensees to ensure that they addressed TMI Action Item lli.D.3.4. This resulted in the GDC 19 dose limits becoming part of their licensing bases.

Comment 32: (Similar comments appeared in 4 individual letters)

. The use of enforcement discretion is addressedin the proposed generic letter, but it only addresses discretion with respect to the test methodology used. The proposed enforcement drscretion wouldpermit use of American Society for Testing and Materials (ASTM) D3803-1989, i

regardless of what testing standard the TS currently specify. The discussions of enforcement discretion should be expanded to also state that discretion willapply to the test acceptance criteria (to permit acceptance criteria consistent with those that willbe approvedin subsequent TS changes, and that are appropriate criteria for use when testing to ASTM D3803-1989).

If the enforcement discretion is not expanded to include use of the more appropriate acceptance criteria, two possible types of unnecessary burden may be placed on licensees:

1. Licensees may choose to accept the NRC recommendation to test using the more conservative testing methodologies of ASTM D3803-1989. Without the expanded enforcement discretion, these plants would need to meet the acceptance criteria in the existing TS. As stated by the NRC in the proposedgeneric letter, the existing acceptance criteria typically have a safety margin of between 5 to 7 to address testing uncertainties and to allow forsome degradation of the charcoalbetween tests. As also noted, when testing to the more conservative ASTM D3003-1989 standard, the NRC will be approving TS acceptance criteria with a safety margin of 2.~ If plants that test to

~ ASTM D3803-1989 are required to meet their existing acceptance criteria (in the interim period until a TS change is approved by the NRC), it is likely that charcoal that would pass the test following receipt of the license amendment might fail the interim criteria.

This result wouldlead to unnecessary replacement of charcoal.

2. Licensees may choose to continue to test using the testing methodology specifiedin existing TS (in order to remain a Group 2 plant as describedin the GL, i.e., plants that do not need enforcement discretion because they are continuing to test in accordance with their TS, but their TS do not specify ASTM D3803-1989). If these Group 2 plants also perform parallel testing in accordance with ASTM D3803-1989 in order to meet the intent of the NRC recommendation, they willbe forced to perform two tests instead of one. Forplants such as the Peny Nuclear Power Plant, that have TS ventilation systems that are run on a continuous basis, this dual testing would need to be

~ performedon a monthlybasis.

i This imposes additional, unnecessary costs for the dual sample testing, a reduction in available sample containers, extra carbon replacement, and additionalburden on the testing facilities.

17 9

i 9

p The expansion of the enforcement discretion and the resulting avoidance of unnecessary burden on licensees as described above are consistent with the NRC Principles of Good Regulation. Under the heading ' Efficient,' as noted within the NRC Principles of Good Regulation, is the statement: 'The American taxpayer, the rate-paying consumer, and licensees are all entitled to the best possible management and administration of regulatory activities. Where several effective attematives are available, the option which minimizes the use of resources should be adapted."

Response

For Part 1 of this comment, the staff has revised the generic letter to specify that the results should meet the acceptance criterion that is derived from applying a safety factor as low as 2 i

- (See the note in Enclosure 2) to the charcoal filter efficiency assumed in the licensee's design-basis dose analysis. For Part 2 of this comment, see the staff's response to Comment 36.

Comment 33: (Nuclear Utility Backfitting & Reform Group-NUBARG)

The attemative to adopting ASTM D3803-1989 is not a realattemative. It is a transparent attempt to force licensees to adopt a new standard selectedby the NRC staff. Having

. previously licensed facilities based on other standards and where the licensee demonstrated

)

conformance with the dose requirements of GDC 19, Part 100, and resolved TMI Action Plan item III.D.3.4, the retroactive imposition of a new testing standard for activated charcoalis impermissible. Byits very terms, the attemative testing protocol called for by staff does not provide a realattemative to ASTM D3803-1989 forlicensees. Under Section 50.109(a), this action is impermissible unless the appropriate backfitting analysis has been completed.

Response

The NRC has decided that the GL is a backfit, but the Section 50.109(a)(3) finding need not be demonstrated in a backfit analysis because the NRC considers the GL to be a compliance

- backfit pursuant to Section 50.109(a)(4)(i). (see response to comment 13). With respect to the issue of a real attemative, the generic letter is not intended by the NRC staff to mandate the use of ASTM D3803-1989 by licensees; a licensee may propose an attemative test protocol to demonstrate charcoal filter functionality. However, if a licensee proposes an altemative test protocol, then the NRC staff expects that the technical adequacy of the attemate test protocol be demonstrated using the same rigorous program that was essential in the development of ASTM D3803-1989.

.s Comment 34: '(Tennessee Valley Authority)

On page 9584 of the Federal Reoister notice, NRC discusses the factor of safety that can be applied when using the new test methodology. Allowance should be made forplants that replace installed charcoal at specified intervals (approximately 5-year intervals), which coincide with the qualified life of charcoal trays. These programmed replacement intervals provide assurance that the charcoal willnot degrade below values assumedin accident analysis when tested within the frequencies providedin the Technical Specifications (TS).

i 18 l

Response

The replacement of the charcoal at certain intervals is an option available to all licensees but is not a requirement. The generic letter already proposes to reduce the safety factor from a value of 5 or 7 in accordance with Regulatory Guide 1.52 to a value of 2. Any further reductions in the safety factor will not provide assurance that the charcoal filter efficiency assumed in the accident analysis will still be valid at the end of the operating cycle. Therefore, the generic letter will not be revised.

Comment 35: (Tennessee Valley Authority)

Requested Action 1 should be clarified to state that forplants that already test to ASTM D3803-1989 and whose TS already reference the standard "no TS amendment and no additional testing is required." Without this clarification, the generic letter could be interpreted to require testing within 60 days for allplants. This proposed revision wouldbe consistent with the

" Response Requested" section, which does not require cubmittal of test information forplants currently testing to ASTM D3803-1989.

Besponse:

The staff has revised Requested Action 1 to clarify that no TS amendment and no additional testing is required for licensees who have TS that require the laboratory testing of charcoal samples for each ESF ventilation system to be conducted in accordance with ASTM D3803-1989.

Comment 36: (Texas Utilities Electric Company)

In the discussion on page 9584 of the Federal Reoister notice, the generic letter " Requested Actions" indicate that testing in accordance with ASTM D3803-1989 should be conducted within 60 days of the date of the genaric letter. Forplants notin Group 1, this would require dual testing untilsuch time as a technicalspecification change is approved by the NRC. In order to avoid the dual-testing requirement, the generic letter should be modified to require adoption of ASTM D3803-1989 after approval of a license amendment.

Response

As proposed in the generic letter, licensees in Groups 3 and 4 have already been granted enforcement discretion to test in accordance with ASTM D3803-1989 during the period of time between issuance of the generic letter and approval of the techncial specification amendment.

Therefore, dual testing is not required for licensees in Groups 3 and 4. To solve the potential dual testing problem for licensees in Group 2, the staff has revised the generic letter to specify that licensees in Group 2 will also be granted enforcement discretion.

Comment 37: (One individual).

Is this a safetyissue? Then whyisn't it being changedimmediately?

19

9

Response

The staff understands that this is not a significant safety issue that requires immediate action which has allowed the staff to develop and implement the proposed resolution in a reasonable time. On the basis of the available laboratory test results, the staff believes that most charcoal in use is not degraded to an extent that would adversely affect control room habitability or public health and safety.. However, the staff also believes, on the basis of the available test results, that there is a group of plants with significantly degraded charcoal and the required test in their

technical specifications is ineffective in identifying the degradation. Because of this group of plants and the group of plants not in compliance with their technical specifications, this issue needs to be addressed. Therefore, the staff has developed this generic letter as a way to resolve this issue in an effective and efficient manner. The overall confidence in charcoal performance, and the low probability of a design-basis accident and the conservatism inherent -

in the design basis dose calculations including the conservatism in the design-basia source

. term, justify the time frame for resolving this matter.

Comment 38: (One individual).

Does the NRC intend to notify licensees that the current Safety Evaluation Reports that have

, been issuedin support of the licenses willbe amended to identify this new requirement that

'mustbe to meet GDC 197 Currently, some SERs document the use of otherstandards to satisfy GDC 19.-

r

Response

In response to the proposed generic letter, all licensees who have TS that do not reference

' ASTM D3803-1989 will be requested to submit a TS amendment referencing ASTM D3803 1989 or an attemate test protocol. A safety evaluation will then be written by the staff which will approving the TS amendment and concluding that the dose limits of GDC 19 are met. This safety evalutaion will supersede the previous safety evaluations regarding charcoal filter testing.

Comment 39: (One individual)

Some licensees were required to comply with 10 CFR 50.34(g), which required a review to the NUREG-0800 Standard Review Plan that was in effect 6 months before to their date of docketing. Will this change require licensees to apply for exemptions to 50.34(g) since this proposed change has not been incorporatedinto their review?

4 10 CFR 50.34(g) requires the applicant to provide the staff with an evaluation identifying any differences from the Standard Review Plan (SRP) acceptance criteria and evaluating how the proposed attematives to the SRP criteria provide an acceptable method of complying with NRC's regulations. As during the licensing process, exemptions from 50.34(g) are not required j

for deviating from the SRP. The SRP is not a ' substitute for the regulations, and compliance is i

not a requirement.

20 i

'5 Comment 40: (One individual)

The technicalspecifications are issued by the NRC as an attachment to the license. Doesn't the NRC have a means to determine the requirements that they have issued to licensees?

Responas:

Yes; but due to the past and present confusion about charcoal filter testing, the staff has

' determined that it is neccessary to have licensees review their current technical specifications requirements and compare them to the test protocol actually being used when the charcoal sample canisters are tested by tne laboratory to determine if the technical specification surveillance requirements are being met.

Comment 41: (One individual)

Does the survey results statement on page 9583 of the Federal Reaister notice mean that the NRCis aware oflicensees who are not in compI!ance with the requirements of the operating license? Why wasnt this corrected through orders or by the NRC initiating technical specification changes?

Response

As discussed in the proposed generic letter, the staff issued emergency technical specification amendments to three plants that were not in compliance with their technical specifications and found through a survey that as many as one-third of the plants may not be in compliance with their technical specifications. Plant-specific orders and NRC initiation of technical specification changes were discussed as possible ways to resolve this issue, but it was decided that a generic letter was a better approach because of the safety significance as discussed in response to Comment 37.

Comment 42: (One individua!)

The Commission should also question the training and qualifications of members of the Committee To Review Generic Requirements (CRGR) who failed to identify this as a change of position that wouldplace a burden on licensees. CRGR should have recognized that licensees would not be able to answer under oath and affirmation since they were already meeting their currentlicensing basis and they had no documentation from NRC to identify what was wrong with the current requirements.

1 Resoonse:

The staff has revised the backfit discussion of generic letter to specify that endorsing the ASTM D3803-1989 testing standard is a new staff position. This has been reviewed and approved by the CRGR. CRGR did recognize that there was adequate documentation from the NRC and industry identifying the problems with the current requirements in 1982, the American Society of Mechanical Engineers (ASME) Committee on Nuclear Air and Gas Treatment (CONAGT) conducted an interlaboratory comparison test using ASTM D3803-1979 and found that seven U.S. laboratories and eight foreign laboratories obtained vastly different 21

4 results when testing samples of the same charcoal. ' After efforts to resolve the differences failed, the NRC contracted with EG&G at !daho National Engineering Laboratory (INEL) to assess the problem.' As a result of this assessment, the NRC issued IN 87-32.- Through IN 87-32, the NRC informed licensees of deficiencies in the testing of nuclear-grade charcoal, specifically noting serious problems with the capabilities of the testing laboratories and with the testing standard (ASTM D3803-1979). The NRC contractor detailed the specific problems in its technical evaluation report, EGG-CS-7653, " Final Technical Evaluation Report for the NRC/INEL Activated Carbon Testing Program." ' Specifically, EG&G reported that

' ASTM D3803-1979 had unacceptable test parameter tolerances and instrument calibration -

j requirements, and that ASTM D3803-1979 was nonconservative in r.ot requiring humidity pre-equilibration of used charcoal.- The information notice indicated that the protocol developed by EG&G could be utilized for performing the laboratory test until the D-28 committee responsible

- for ASTM D3803 revised the standard. The committee completed the revision and issued it in December 1989.

Following the issuance of IN 87-32, responsible licensees revised their technical specifications

= to test their charcoal in accordance with ASTM D3803-1989.

' Comment 43: (Commonwealth Edison Company)

On page 9584 of the Federal Reaister notice (Requested Actions), the statement is makte: *1. If your current TS require the laboratory testing of charcoal samples for each ESF ventilation system to be conductedin accordance with ASTM D3803-1989, then no TS amendment is required." This shouldbe reworded as follows: ' Stations that currently reflect the acceptance criteria for testing ESF ventilation systems to D3803-1989 without the safety factor of 2 being applied, may want to consniersubmitting a TS amendment to allow laboratory results that include the safety factorof 2.'

Response

This proposed revision is not necessary. Once the generic letter is issued,'any station with technical specifications that reference ASTM D3803-1989 without a safety factor of 2 can submit a technical specification amendment to the staff utilizing a safety factor of 2 for review and approval.

~

Comment 44: (Commonwealth Edison Company)

On page 9589 of the Federal Reaister notice, the following formula appears:

Allowable Penetration = [100% MethylIodide Ef6ciency for Charcoal Creditedin SERySafety Factor

. The equation should be revised as follows:

Allowable Penetration = [l00% - Methyllodide Efficiency for Charcoal Creditedin Accident AnalysisySafetyFactor g

IJse of the efficiency credit in the accident analysis is more accurate because it reflects current assumptions and analysis versus those assumedin the original SER.

22

f.

I L

a.

Response

l The staff has revised the equation in the sample technical specification note in Enclosure 2 of the generic letter to state:

Allowable Penetration _= [100% -. Methyl lodide Efficiency

for Charcoal Credited in the Licensee's Accident Analysis)/ Safety Factor

This value should be the efficiency that was incorporated in the licensee's accident analysis L

which was reviewed and approved by the staff in a safety evaluation.

Comment 45: (Consolidated Edison' Company of New York, Inc.)

Will the tertiary document be the final document to which the licensee is held accountable? At present, many Technical Specific.ations simply require the use of Regulatory Guide 1.52. This

' document specifies the use of a secondary document (i.e., ANSI N509), which in tum specifies a tertiary document (i.e., RDTM16). Will ASTM D3803-1989 be the final, non-technical-spectfication-cited document to which the licensee willbecome committed? If not, will there be forthcoming additoonal commitments required to fourth-level documents specified from ASTM D3803-1989 (such as D 1193, ' Specification for Reagent Water," or MIL-F-51068D,

" Filter, Particulate, High Efficiency, Fire Resistant,"etc.)? These reference documents, if updated, could cause changes to the testing method describedin ASTM D3803-1989. Willit.

become incumbent on the licensee to comply with changes in these documents or verify vendor compliance with the requirements of these documents?

Response

The proposed generic letter requests that plants revise their technical specifications to test in accordance with ASTM D3803-1989, which would then become the primary document. The

- ASTM D3803-1989 test standard allows the use of updated reference documents because it does not specify the specific date of the reference document. The staff only requires plants to revise standards in their technical specifications if it can be shown that there are significant problems with the standard that may result in the licensee not being able to meet the requirements.' Therefore, the staff expects this to be the final document to which licensees will be held a d'Jntable in their technical specifications, but the possibility for future changes exists if sub si&! new problems are identified.

Comment 46: (First Energy)

The prop 05&d generic letter doesn't address an estimated timeframe for approval of the TS revisions based upon the generic letter or specifically address whether submitted TS revisions are going to be expedited for approval. If the enforcement discretion is not expanded to include the acceptance criteria, as previously recommended in Comment 2, then plants will be

- burdened with extra expenses until the NRC completes its processing of the TS change.

Therefore, timelyprocessing would be essential.

23 l

i 4

Response

The staff will review all of the submitted technical specification amendments in an expedited manner. Requested Actions items 2 and 3 ask the licensee to indicate when the next laboratory test is scheduled to be performed so the staff can prioritize its review efforts. In addition, the staff has revised the generic letter to specify that a safety factor as low as 2 can be used during the period of time between issuance of the generic letter and approval of the technical specification amendment. (See response to Comment 36.)

Comment 47: (Similar comments appeared in 10 individual letters)

We endorse the comments submitted by the Nuclear Energy Institute (NEI) in a letter dated March 27,1998 on this proposed generic letter.

Response

In the above discussion of the comments, the staff has provided a response to all of NEl's comments regarding the proposed generic letter.

s'

}

2 l

24

l-Appendix A," Alphabetical List of Respondents" l..

-1! Arizona Public Service Company

13. Nuclear Energy Institute (NEI)

Palo Verde Nuclear Generating Station 1776 i Street, NW

' Mail Station 7605.

Suite 400 P.O. Box 52034 Washington, DC 20006-3708

' Phoenix, AZ 85072-2034

14. Nuclear Utility Backfitting & Reform Group

2. Baltimore Gas and Electric Company Winston & Strawn

. Calvert Cliffs Nuclear Power Plant 1400 L Street, N.W.

l-l 1650 Calvert Cliffs Parkway '

Washington, DC 20005-3502 Lusby, MD 20657 -

15. NUCON Intemational, Inc.

3. Carolina Power & Light Company P.O. Box 29151 P.O. Box 1551 7000 Huntley Road 411 Fayetteville Street Mall Columbus, Ohio 43229 Raleigh, NC 276021 16.' Omaha Public Power District i

L

4. Cleveland Electric lliuminating Company Fort Calhoun Station l.

Perry Nuclear Power Plant 444 South 16th Street Mall 10 Center Road Omaha, Nebraska 68102-2247 -

).

P.O. Box 97.

l-Perry, Ohio 44081 '

17. PECO Energy Company 965 Chesterbrook Boulevard -

5. Comnonwealth Edison Company Wayne, PA 19087-5691 1400 Opus Place Downers Grove, IL 60515-5701

18. Southem Califomia Edison San Onofre Nuclear Generating Station

6. Consolidated Edison Company of New York P.O. Box 128 Indian Point Station San Clemente, CA 92674-0128 Broadway & Bleakley Avenue Buchanan, NY 10511

19. Tennessee Valley Authority 1101 Market Street 7.' Entergy Operations, Inc.

Chattanooga, TN 37402-2801 P.O. Box 31995 -

' Jackson, MS 39286-1995 -

20. Texas Utilities Electric Company L

Comanche Peak Steam Electric Station

8. Eugene F. Kurtz, Jr.

P.O. Box 1002

. P.O. Box 164 Glen Rose, Texas 76043-1002 Shippingport, PA 15077

21. Toledo Edison Company i

9. Florida Power & Light Company Davis-Besse Nuclear Power Station P.O. Box 14000 5501 North State Route 2 Juno Beach, FL 33408-0420 Oak Harbor, Ohio 43449-9760 l

10. NCS Corporation.

22. Virginia Power j

4555 Groves Road, No. 41 Innsbrook Technical Center i

. Columbus, Ohio 43232 5000 Dominion Boulevard Glen Allen, Virginia 23060

- 11.' New York Power Authority -

123 Main Street -

23. Wisconsin Public Service Corporation

. White Plains, New York 10601 -

Kewaunee Nuclear Power Plant North 490, Highway 42

12. North Atlantic Energy Service Corporation Kewaunee, WI 54216-9511 P.O. Box 300.

Seabrook, NH 03874

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