ML20212H998

Forwards Comments on Draft SER Re Design Baseline & Verification Program,Responses to Two Open Items & List of New Commitments

ML20212H998
Person / Time
Site:	Sequoyah
Issue date:	02/27/1987
From:	Gridley R TENNESSEE VALLEY AUTHORITY
To:	Youngblood B NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), Office of Nuclear Reactor Regulation
References
NUDOCS 8703060276
Download: ML20212H998 (16)

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TENNESSEE VALLEY. AUTHORITY CH ATTANOOGA, TENNESSEE 374ol SN 157B Lookout Place FEB 271987 U.S. Nuclear Regulatory Comission Attn: Document Control Desk Office of Nuclear Reactor Regulation Washington, D.C. 20555 Attention: Mr. B. J. Youngblood In the Matter of ) Docket Nos. 50-327 Tennessee Valley Authority ) 50-328 SEQUOYAH NUCLEAR PLANT - DRAFT SAFETY EVALUATION REPORT - DESIGN BASELINE AND VERIFICATION PROGRAM The draft Safety Evaluation Report (SER) on the Design Baseline and Verification Program (DBVP) transmitted to TVA on-January 20, 1987, from B. J. Youngblood to S. A. White has been reviewed by TVA. TVA coments on the draft SER and responses to the two open items listed in the cover letter to the draft SER are contained in enclosure 1 of this submittal.

Enclosure 2 consists of new comitments made within enclosure 1.

If you have any questions concerning this issue, please call Beth L. Hall of the Sequoyah Site Licensing Staff at (615) 870-7459.

Very truly yours, TENNESSEE VALLEY AUTHORITY

/

R. Gridley, irector Nuclear Safe y and Licensing Enclosures cc: see page 2

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B703060276 870227 PDR I P ADOCK 05000327 PDR I

An Equal Opportunity Employer

U.S. Nuclear Regulatory Comission cc (Enclosures):

U.S. Nuclear Regulatory Commission Region II Attn: Dr. J. Nelson Grace, Regional Administrator 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 Mr. J. J. Holonich Sequoyah Project Manager U.S. Nuclear Regulatory Commission 7920 Norfolk Avenue Bethesda, Maryland 20814 Mr. G. G. Zech, Director TVA Projects U.S. Nuclear Regulatory Commission Re51 on II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 Sequoyah Resident Inspector Sequoyah Nuclear Plant 2600 Igou Ferry Road Soddy Daisy, Tennessee 37379 i

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ENCLOSURE 1 The following sections represent TVA's comments on the NRC's draft Safety Evaluation Report (SER) on the Design Baseline and Verification Program (DBVP) issued on January 20, 1987.

RESPONSE TO OPEN ITEMS

1. NRC CONCERN Develop a more comprehensive approach for a drawing control system which includes scheduling details and identification of all other drawings to be maintained as configured.

RESPONSE

In the December 11, 1986 letter to NRC (reference 1), TVA briefly described the two steps planned to implement the permanent design control system. These are the transitional system and the permanent system. Both systems are based upon conversion to a single drawing system. As modifications are made to drawings, the drawings will be converted to Configuration Control Drawings (CCDs). TVA is presently finalizing the list of Primary Control Room drawings as a restart commitment (reference 3) and is also evaluating the types of drawings which will be maintained in an as-configured condition on a long-term basis (reference 4). TVA is presently developing a list of drawings required to be maintained as-configured, based upon INPO Good Practice DE-101. This will be done to ensure proper operation, maintenance, and design integrity of safety-related portions of the plant. The list of drawings to be maintained as-constructed for Sequoyah unit 2 will be provided to NRC by March 21, 1987.

2. NRC CONCERN Inclusion of the ice condenser, permanent hydrogen mitigation system (i.e., igniters) and hydrogen analyzers in Phase I of the DBVP.

RESPONSE

l NRC has questioned the DBVP Phase I scope for exclusion of the ice condenser system, permanent hydrogen mitigation system, and hydrogen analyzers. TVA responded in a December 11, 1986 letter to NRC (reference 1) with the

, following information:

l The restart portion (Phase I) of the DBVP is reviewing systems and l subsystems required to mitigate Final Safety Analysis Report (FSAR) l Chapter 15 design basis accidents. For such an accident, several days will pass before the hydrogen concentration would reach a sufficient level as to be a concern according to Sequoyah FSAR l

Chapter 15 analysis. Present system operation procedures (SOI-83.1) i require the hydrogen recombiners to be placed in operation within the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after an event or when hydrogen concentration l

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reaches a preset level as measured by the hydrogen analyzers. This preset level measured by the hydrogen analyzers is required to mitigate events beyond our design basis (i.e., inadequate core cooling events). Events discussed in Chapter 15 of the FSAR would be mitigated adequately by placing the hydrogen recombiners in service within first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. For this reason, the hydrogen analyzers were not considered in Phase I of the DBVP.

t NRC's draft SER on the DBVP states that the staff's position on this issue is' that these systems or subsystems are appropriate-for inclusion in the Phase I portion of the DBVP.

-On January 21, 1987, during a meeting with NRC staff members in Bethesda, Maryland, TVA proposed an alternative technical assessment to that of inclusion of these systems in Phase I of the DBVP. This proposal is currently being assessed by the NRC staff. TVA has now completed this effort.

Basically, the effort is similar to the process presently being performed per SQEP-28. " Procedure for Evaluating ECNs, Cat D FCRs, FCNs, LDCRs, and TACFs Not Reviewed by Design Baseline and Verification Program." This effort meets-the objectives of the DBVP stated in the NPP, Volume 2, and the DBVP Program Plan (reference 5), but was performed in lieu of a full DBVP effort for those systems.

This technical assessment included the following:

TVA performed an evaluation of changes since OL on the safety-related portions of the hydrogen mitigation system, hydrogen analyzers, and ice-condenser system. These changes include Engineering Change Notices (ECNs), Field Change Notices (FCNs), Field Change Requests (FCRs),

( Temporary Alteration Control Forms (TACFs), Local Design Change Requests (LDCRs) and Category D FCRs. The evaluation complies with the objectives of the DBVP as follows:

o To verify the adequacy of the plant modifications made since OL to systems, or portions of systems, required to mitigate design basis events and to provide for safe shutdown of the plant.

o To provide confidence that the modifications are supported by engineering analysis and documentation.

o To provide confidence that the modifications are made in conformance with licensing commitments.

These objectives were met by TVA's review, which accomplished the following:

a. Identified changes (i.e., ECNs, FCRs, FCNs, TACFs, LDCRs, and Category D FCRs) involving systems 43/83 and 61 (hydrogen mitigation, hydrogen analyzers, and ice condenser systems, respectively).

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b. Identified all changes that can affect the safety-related functions of these systems.

c. Evaluated these changes (item b above) against the design source documents (FSAR, design criteria,; technical specifications, or other codes and standards, as required) to determine whether any of the changes will reduce these systems' abilities to perform their designated safety function (s).  !

d. Where necessary, Unresolved Safety Question Determinations (USQDs) l and Unimplemented Design Item Evaluations (UDIEs) were completed or l l revised in accordance with TVA procedures. (A UDIE is an evaluation '

i of unimplemented design work performed to confirm that the design l implementation is not required for a particular milestone.) 2

e. No deficiencies were identified from this review that require I corrective action.

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f. A final report was issued to document the DNE evaluation of the containment integrity review performed on all change documents affecting system 61 (ice condenser) and systems 43/83 (hydrogen l-._ mitigation). This included a second review, specifically I concentrated on the impact on the system's function, of change documents previously reviewed under SQEP-12 or SQEP-28. One hundred and forty-one ECNs and fourteen LDCRs were reviewed by this program.

The review determined that no TACFs, Category D FCRs, or FCNs applied to these systems. No degradation of the ability of the ice condenser or the hydrogen mitigation systems to perform their safety functions was found.

In conjunction with this technical assessment, other activities and tests are being performed that provide additional input into the abilities of these systems to perform their functions. This additional input includes the following:

Ice Condenser System The portions of the Ice Condenser added under the new scope include the lower inlet doors, internals of the Ice condenser, intermediate deck doors, top deck blanket, and the 12-inch drain lines to the lower compartment. The only items required to perform an active function j during any event are the intermediate deck and lower inlet doors, top i deck blanket, and the 12-inch drain lines.

Lower Inlet Doors, Intermediate Deck Doors, Top Dock Blanket of the items discussed above, the lower inlet doors, intermediate deck doors, and top deck blanket are the most important, as they have to perform active functions. To ensure these functions are available, several activities are performed periodically. Surveillance Instruction SI-108 is performed to ensure that the doors are operable. This instruction ensures that the doors and blanket

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are not frozen, binding, or that any other condition exists that could

-prevent the doors and blanket from functioning. This instruction also requires a pull test on the lower and intermediate deck doors to ensure that excessive force is not required for the doors to open. The Ice Condenser is designed to be basically a passive system, and with the assurance from the periodic surveillance that the doors will open properly, the function of cooling the containment will be performed.

12-Inch Drain Lines The original design of the Ice condenser system did not require the 12-inch drain lines to perform a safety function. Changes have occurred to the plant design since then, and the drain lines now perform functions associated with mitigation of some accidents. These functions include ensuring that the water from the Ice Condenser is drained to the inside of the crane wall and ensuring that proper distribution of the flow from the

! drains sids in the mitigation of a potential release of superheated steam due to a steam line break.

To ensure that the water from the Ice Condenser is delivered to the inside of containment, the. drain lines must be able to withstand the forces of a seismic event and those of an event that would cause ice melt. This concern has been identified by a Condition Adverse to Quality (CAQ)

Problem Identification Report (PIR) SQKNEB8634 independently of the DBVP i

and must be resolved before restart. By performing a stroke test on the l valve disc, Surveillance Instructions SI-166.11 and -166.12 ensure that check valves on the drain lines are operable and will open when there is flow through the lines.

As the 12-inch drain lines must now ensure a proper distribution of water from the Ice Condenser to aid in the mitigation of potential superheat, a design review of the drain lines was performed for Sequoyah to ensure that this function would be accomplished. This review included a field inspection of the drain lines inside containment to verify that the l installation complies with the new design requirements. This review j resulted in modification to two of the lines and will ensure that after the modifications are complete, the drain lines will provide adequate protection against superheat (resolution of PIR SQNNEB8634).

l l Combustible Gas Control i The additional scope of the Hydrogen Mitigation System includes the functional aspect of the Hydrogen Analyzers and the Hydrogen Ignition i

System.

i Hydrogen Mitigation System i This syster was added to Sequoyah in response to NUREG-0737. The only L changes to this system after the initial installation have been to convert the interim system to the permanent Hydrogen Mitigation System. Design Criteria have existed from the original conception of the system; and i

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all aspects of this system, including design changes, have been previously reviewed by NRC as part of NRC's post-TMI Hydrogen Mitigation Program.

Surveillance Instruction SI-305.2 checks current and voltage from each circuit to ensure that a minimum number of igniters (33) are available to adequately mitigate any event that would require their use. This SI also ensures that the igniters can reach a minimum specified temperature to ensure that they will perform as required.

Hydrogen Analyzers The existing DBVP includes the Hydrogen Analyzers from the standpoint of containment isolation. This ensures pressure boundary integrity of the system. Surveillance Instruction SI-219 is performed periodically on the Hydrogen Analyzers to ensure the functionality of the analyzer system.

This activity tests the system by emitting a one-percent, four-percent, and eight-percent. concentration of gas to the analyzers and verifying that the analyzers can accurately detect, measure, and indicate these concentrations of the gases. A weekly test, SI-287, performs the same test but only at concentrations of one percent and four percent. These activities, coupled with the review performed in the existing DBVP, will ensure that the system can perform required functions.

Summary In addition to the periodic testing, a technical assessment of the changes to these systems has been accomplished. No degradation of the ability of the system to perform their safety functions were identified. These activities provide assurance that the changes do not degrade the abilities of these systems to perform their safety functions.

Clarification of Statements TVA proposes the following revisions or clarifications of statements made l within the draft SER on the DBVP.

1. Revise page 3-2, third paragraph, items 1-4 to read:

a. Evaluate existing and proposed plant modifications to minimize changes;

b. Review plant modifications, both hardware and software, to ensure that line managers are accomplishing the changes in accordance with adequate design and configuration controls; t

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c. Ensure that necessary interface and implementing procedures exist to

' establish a closed loop system for modifications in order to maintain design integrity; and

d. Ensure statusing of ECNs and associated design and plant implementing documents is adequate to reflect the status of the modifications.

2. Clarification of page 3-2, fourth paragraph:

It should be noted that the provisions of the new transitional design control process were not in effect at the time of the July 28, 1986 inspection. Sequoyah Engineering Procedure (SQEP)-13. " Procedure for Transitional Design Change Control," now in effect, does require that the requirements listed be included as part of the modifications packages.

3. Clarification of page 3-3, first paragraph:

The scope of TVA review of workplans issued after the Postmodification Task Force completed its review encompasses the 37 systems or portions of systems included in the DBVP, Phase I.

As stated in-a TVA letter to NRC dated October 31, 1986 (reference 7),

TVA committed to review modification workplans on the DBVP Phase I scope of systems or portions of systems to verify adequacy of testing. This review does include electrical, nuclear, civil, and mechanical systems within the DBVP, Phase I scope.

! 4. Page 3-7, second full paragraph:

a. Revise third " bullet" to read:

Facility modifications implemented or proposed since the issuance of the operating license. These will be evaluated against the (updated) design-basis documents to determine their technical adequacy.

Additionally, ECNs will be assessed to ensure that a partial implementation or nonimplementation will not reduce the system's ability to perform its designated safety function or will not violate

! licensing commitments.

b. Revise fourth " bullet" to read:

System evaluations using the modification evaluation and walkdown results as inputs. These will be used to verify that the functional aspects of the systems, or portions of systems, identified in the DBVP to mitigate FSAR Chapter 15 Design Basis Accidents and to accomplish a safe shutdown, have not been degraded below acceptable design limits and that these modifications have not violated i licensing commitments.

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E9Ig: while the wording in the draf t SER of item four (above) is consistent with that in Volume 2 of the TVA Nuclear Performance Plan (NPP), the suggested revisions more accurately reflect the activities performed in the DBVP. They are consistent with the TVA submittal dated

December 31, 1986 (reference 2), in which information supplemented to Volume 2 was presented.

5. Clarification'of page 3-3, next to last paragraph:

The draft SER states that the original SER for Sequoyah (NUREG-00ll) and l its Supplement I contain a staff position that the Residual Heat Removal (RHR) system for Sequoyah must meet the requirements of Branch Technical Position (BTP) RSB 5-1 for reaching cold shutdown with safety-grade equipment. This statement is inconsistent with the staff position taken i in Supplement 1 and indicates a need for further discussion between TVA j- and NRC, as Sequoyah's RHR system does not meet the requirement for j achieving cold shutdown with safety-grade equipment. For example, 2

Sequoyah does not meet the BTP requirement that the RHR system be single-failure proof, as it has only a single suction line with isolation ~

valves in series. This fact was recognized by the staff in NUREG-00ll.

, The design basis for Sequoyah is hot standby, and the analyses discussed in Chapter 15 of the Sequoyah FSAR only consider bringing the plant to

! hot standby. This is the basis for consideration of design basis i accidents used in the selection of systems within the scope of the DBVP, Phase I.

6. Clarification of page 3-10,~1ast paragraph:

I As previously committed in reference 1. TVA will provide the detailed information describing the postrestart phase (Phase II) of the program on j or before March 21, 1987. That information will cover the particulars of the program; however, it should be pointed out that the definition of the long-term fixes for design control problems has been provided in several l submittals to NRC and is partially described in the draft SER.

l Previous submittals to NRC that describe the long-term fixes include:

( a. NPP, Volume 2, Section 3.0 - organizational improvements Change

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Control Board, Transitional and Permanent Design Control Systems.

b. TVA letter dated January 21, 1987 (reference 4) - long-term drawing

! control program.

c. TVA letter dated February 3,1987 (reference 6) - creation and

' maintenance of the C/R data base and preparation of design criteria.

d. TVA letter dated August 18, 1986 (reference 8) - Sequoyah design control issues.

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l TVA has developed a new comprehensive design control program which '

provides the long-term fixesoto the weaknesses of the past programs. The 1 transitional design control program has been instituted, and '

implementation of the permanent design control system will begin by December 31, 1987. References 1, 3, and 4 provide some major milestones for the conversion to " single drawings" and completion of Phase II design ,

criteria. '

Additional Information/ comments 9 I

1. Page 3-2, third paragraph: I A. Region II inspection of interim design control measures was conducted in November 1986 and will be documented in IE Report Nos. 50-327/86-62

, and 50-328/86-62. TVA acknowledges that the issue is open, pending KRC i inspection and approval of field implementation of modifications packages.

2. Page 3-3, second paragraph and following, through Section 3.1.3 Findings:

l In reference 1, TVA committed to begin implementation of the permanent design control system by December 31, 1987, with additional details

, provided in reference 4. This commitment will require that upper-tier

! procedures, Nuclear Engineering Procedures (NEPs), be issued by l June 30, 1987, in order to allow for incorporation of changes into the

} SQEPs and to provide for training in use of the new procedures by the implementation date. In addition, changes to Nuclear Quality Assurance i Manual (NQAM) and plant procedures other than SQEPs will be made, as

! appropriate, to support the permanent design control process.

Please refer to the previous TVA response to open item (1) for additional l information on this issue.

3. Page 3-10, first paragraph:

TVA acknowledges that the issue of the DBVP including only the plant modifications made since issuance of the OL is still under staff review.

TVA's justification for this aspect of DBVP scope was provided in reference 1 in response to NRC Request for Additional Information dated September 9, 1986.

4. Page 3-11. Section 3.2.4 Findings:

NOTE: References to observation numbers correspond to Observations as documented in IE Report Nos. 50-327/86-38 and 50-328/86-38.

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A. NRC CONCERN

a. Inconsistencies between the walkdowns of Units 1 and 2. -These stem from the excessive latitude given to system engineers on what was to be included in the walkdowns.

RESPONSE

. The walkdown process is incomplete on unit 1. Only the basic functional walkdowns have been performed on unit 1; therefore, the supplemental and final walkdowns have yet to be performed. The system engineers were given some latitude in determining their respective walkdown_ boundaries, but they are required to provide technical justification in their system p evaluations for any item not walked down. This is required by SQEP-16,.

" Procedure for System Evaluation and Development of System Evaluation-Report," Section 3.3.5.

This is still an open item, pending additional inspection in March 1987.

It is documented as Observation Nos. 1.1, 3.1, 6.3, and 7.1.

b. Lack of verification of portions of system drawings where portions of the system appeared on more than one drawing, i RESPONSE The DBVP system walkdowns were performed within the boundaries identified by the DNE system engineer in the walkdown packages. If a portion of a system within the scope of the program was shown as "out-of-function" on a drawing, that portion was walked down using the detailed drawing that depicts the area as "in-function." The Sequoyah project engineer has recently issued clarification of the Sequoyah Engineering Project policy concerning out-of-function drawing information. This clarification of l policy directs that, at Sequoyah, out-of-function information should only be provided on drawings when it significantly improves the clarity of a system or drawing interface. When used, out-of-function information

! should be limited to the first in-line valve. Branch lines prior to the first in-line valve should also be limited to the first valve. Other

- existing out-of-function information should be removed from the drawing.

Out-of-function information should be accurate but should not be used for

design, operation, modification, or maintenance of the plant.

l This is still an open item, pending additional inspection in March 1987.

It is documented as observation 1.3.

c. Failure to document decisions regarding walkdown limits when they were less inclusive than program boundaries.

RESPONSE

SQEP-16, Section 3.3.5, requires that portions of systems within the scope of the boundary calculation (SQN-OSG7-048) that were not walked down must be technically justified in the SYSTER.

i This is an open item, pending additional inspection in March 1987. It is

,' documented as Observation 1.2.

B. NRC CONCERN The scope of the walkdowns. At the time of the first inspection, the scope of the walkdowns did not include physical (or other) verification of instrumentation and electrical aspects, such as conformance of system functionality to logic diagrams, etc. These aspects can, however, be verified by review and evaluation of test results.

RESPONSE

TVA concurs and is using review and evaluation of test results for verification of instrumentation and electrical aspects; however, the scope of the electrical walkdowns has been increased. Details regarding this effort are provided in a TVA letter to NRC dated February 3,1987, which addresses the item, Observation 5.1, (reference 6).

C. NRC CONCERN Development of procedures and criteria. TVA is developing procedures and criteria as the program progresses. This may result in accommodating the procedures to the actual work performed.

RESPONSE

Procedures were developed within a timeframe to ensure that the implementors received training on how to use the procedures so that the products met the procedures' requirements. Some of the DBVP tasks were initiated before the applicable procedures were issued and training completed; however, any work performed before such time was reviewed to ensure that it met the necessary requirements. Output documents were signed and reviewed after the procedures were issued and training was conducted.

All procedures undergo an extensive review process before they are issued, l

including a review by the Engineering Assurance (EA) organization. This ensures that they comply with the requirements of the DBVP plan, Quality Assurance requirements are appropriately addressed, and that the tasks i performed per these procedures will be technically adequate.

This item is not documented as an Observation, but is identified as a general concern.

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.D. NRC CONCERN ,

. N i The EA review of the Design Baseline and Verifieration program. The review does not include sufficient guidance on determining which s i review products should be samplod. m s /

Response _, 4 The EA Oversight Review team.lnader provided the follow'ing guidance for

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i-sample size and sample selection in Revision 0 of the Program [lgn for the

, EA Independent Oversight Review for the Sequoyah PbJp (docketed by ref4rence 5): ,

7 4 When appropriate, an initial. sample size of approximately 5 -f -

percent will be selected for review. Th,ii may be altered, '

higher or lower, depending upon tha nature of the activity being reviewed and of the results be,ing obtained daring the '

review. The review process will select samples frem work ,

accomplished during the initial, intermediate, and final phases of each activity bking . implemented by the project

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-wherever practical. This will ensure that the project's s ,

l evaluation process has not been significantly.affected over the program duration or by changes in personnel.

• In addition to this information, the team leader'provided verbal instructions to the team members which included the following guidance:

The basis of samp'i' l selection will.be dependent upon history of '.

reported problects, significant interdisciplinary interfaces -

and/or known significant design modifications. Specific criteria for sample selection is included in the individual discipline '

review plans.

i The latter guidance has been incorporated into R'evision 1 of' the

! subject program plan. This revision is currently under review > /

for issuance. , i i

• This item (Observation 4.3) has been reported as closed in IE

' Report Nos.' 50-327/86-55 and 50-328/86-55, dated February 3,1987.

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E. NRC Concern The-computerized list of licensing commitments and. design requirements (called the " Commitment / Requirement Data Base,"

and developed by TVA/Impell). This list was not independently verified. For example, quality assurance controls were not applied to the information retrieval process.

RESPONSE

Quality Assurance controls were applied to the entire process, including the information retrieval process (i.e., the entire process was controlled by procedurca and subject to IUL review).

However, procedures controlling the C/R data base and design ,

criteria preparation did not require an independent verification of the C/R data entries. This is appropriate, given the nature of the work and use of the data base. The C/R data base was intended as an enhancement tool in the preparation of.the design criteria. A more detailed discussion of this issue, including maintenance of the C/R data base is provided in a TVA letter to NRC dated February 3, 1987 (reference 6).

This item is documented as Observation 5.4 and again as a concern in IE Report Nos. 50-327/86-45 and 50-328/86-45.

6. Page 3-12, 3.2.5 Conclusion TVA believes that the DBVP, conceptually and as implemented, does provide sufficient information to both TVA and NRC staff to make l -the~ statement that the adequacy of past modification work has l been thoroughly assessed and that deficiencies in the previous l design control process are being corrected. While recognizing i that the DBVP has yet to be completed and fully assessed by TVA l

and NRC, with the information gained from the full implementation of the Sequoyah DBVP and with implementation of the improved design control system, TVA has cc.t:fidence that the design control issue at Sequoyah will be adespat ily addressed.

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4 CORRESPONDENCE REFERENCES

1. TVA letter from R. L'! Gridley to B. J. yYoungblood dated December 11,1986, "Sequoyah Nuclear Plant - Additional Information on Sequoyah Design Baseline and Verification Program."

2. TVA letter from R. L. Gridley to B. J. Youngblood dated December 31, 1986, "Sequoyah Nuclear Plant - Supplemental Information to NRC for Design Baseline and Verification Program."

3. TVA letter from R. L. Gridley to J. Nelson Grace dated December 12, 1986, "Sequoyah Nuclear Plant Unit 2 - Restart Program for Drawing Update."

4. TVA letter from R. L. Gridley to J. Nelson Grace dated January 21, 1987, "Sequoyah Nuclear Plant Unit 2 - Long-Term Drawing Control Program."

5. TVA letter from R. L. Gridley to J. M. Taylor dated June 27, 1986, "Sequoyah Nuclear Plant (SQN) 'Jnits 1 and 2 - Design Control Program Information."

6. TVA letter from R. L. Gridley to J. M. Taylor dated February 3,1987, "Sequoyah Nuclear Plant - Response to Items From Inspection Report Nos. 50-32 7, ~328/86-38 and 50-327, -328/86-45. "

7. TVA letter from R. L. Gridley to J. Nelson Grace dated October 31, 1986, "Sequoyah Nuclear Plant (SQN) Units 1 and 2 - NRC -

OIE Region II Inspection Report 50-327/86-43 and 50-328/86 Response to Violations Nos. 50-327/86-43-02 and 50-328/86-43-02."

8. TVA letter from R. L. Gridley to B. J. Youngblood dated August 18, 1986, regarding responses to five design control questions about Sequoyah Nuclear Plant.

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ENCLOSURE 2 LIST OF NEW COMMITMENTS FOR SEQUOYAH CONTAINED IN ENCLOSURE 1

1. Engineering Assurance will issue the upper-tier procedures (Nuclear Engineering Procedures - NEPs) required for development of Sequoyah procedures controlling the permanent design control process. These NEPs will be issued by June 30, 1987.

2. Provide to NRC by March 21, 1987, a list of drawings required to be maintained as-constructed.

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