ML19310A971

Requests Preliminary Evaluation of Licensee Response to NRC 791023 Interim Position for Containment Purge & Vent Valve Operation Pending Resolution of Isolation Valve Operability, Generic Item B-24.Evaluation Form Encl

ML19310A971
Person / Time
Site:	Prairie Island
Issue date:	12/27/1979
From:	Reeves E Office of Nuclear Reactor Regulation
To:	Office of Nuclear Reactor Regulation
Shared Package
ML19310A968	List: ML19310A967 ML19310A970 ML19310A971
References
TAC-42588, TAC-42603, TAC-42604, TAC-44877, TAC-44878, TAC-51984, TAC-51985, NUDOCS 8007010585
Download: ML19310A971 (6)

Text

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MEMORANDUM FOR: All DDR Project Managers FROM:

Ed Reeves, Project Manager Lead '3eneric Task B-24, Containment Purging and Venting

SUBJECT:

1)

PRELIMINARY. EVALUATION OF RESP 0l:SE TO INTERIM MRC POSITION 2)

INFORMATION RELATING T0 LONG-TERM REVIEW 0F B-24 q

TASK On October 1979 the NRC Staff " Interim Position for Containment Purge and Vent V ve Operation Pending Resolution of Isolation Valve Operability" was sent to all licensees of operating reactors. The interim position responses were requested within 45 days of receipt of the letter by the licensee.

Responses should be arriving this week.

.Thus, each of you is requested to determine if the licensee's commitment fully meets the interim position, specifically items 1 and 2 of the attached enclosure.

Assistance is available to aid you in making this & cision.

However, since the staff position was sent to each licensee in the 10 CFR 50.54(f) format, pur recommendation is important and is necessary to assist in the determination of whether or not the license should be modi-fied, suspended, or revoked.

On this basis, you are requested to review the licensee's submittal against the " Interim NRC Position" and obtain any technical assistance from the assigned review team rembers, or myself. When your preliminary evaluation is complete, the attached form should be completed and routed for internal y

73r>jjfe concurrences.

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As a reminder, the long term review of B-24 is continuing.

Questions are being developed by the separate technical review sections as their long term review continues. These long-term questions should be sent to the licensee, but clearly marked to indicate that the questions relate to the long-term solution.

Likewise, any future questions developed for the

" Interim Position" should clearly reference our October 23, 1979 consnitment request.

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c Edward A. Reeves, Lead Engineer B-24 Task Operating Reactors Branch #1, D0R Attachments:

1.

Interim Position 2.

Preliminary Evaluation Fonn 8007010

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INTERIM POSITION FOR CONTAINMENT PURGE AN: 7ENT VALVE OPERAT!CN PENDING RESOLUTION OF ISOLATION VALVE OPERABILITY Once the conoitions listed below are met, restrictions on use of the containment purge.and vent system isolation valves will be revised based on our review of your responses to the November 1978 letter justifying your proposed operational mode. The revised restrictions can be established separately for each system..

1.

Whenever the c'ontainment integrity is requirkd, emphasis should be placed on operating the containment in a passive mode as much as possible ano on limiting all purging and venting times to as low as achievable.

To justify venting or purging, there must be an established need to improve working conditions to perform a safety related surveillance or safety related maintenance procedure.

(Examples of improved working conditions would include deinerting, reducing temperature *, humidity *,

and airborne activity sufficiently to permit efficient performance or to significantly reduce occupational radiation exposures), and

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2.

Maintain the containment purge and veht ' isolation valves closed whenever tne reactor is not in the cold shutdown or refueling mode until such time as you can show that:

a.

All isolation valves greater than 3" nominal diameter used for containment purge and venting operations are operable under the most severe design basis accident flow condit. ion loading and can close within the time limit stated in your Technical Specifications, design criteria or operating procedures. The operability of butter-fly valves may, on an interim basis, be ceconstrated by limiting the valve to be no more than 30' to 50' open (93* being full open). The maximum opening shall be determined in consultation with the valve supplier. The valve opening must be such that the critical valve parts will not be damaged by DBA-LOCA loads and that the valve will tena to close when the fluid dynamic forces are introduced, and b.

Modifications, as necessary, have been made to segregate the containment ventilation isolation signals to ensure tha, as a minimum, at least one of the automatic safety injection actuation signals is uninhibited and operable to initiate valve closure when any other isolation signal may be blocked, reset, or overridden.

• uniy wnere temperature and humidity controls are not in the present design.

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A' tach:2nt 2-t PRELIMINARY EVALUATION INTERIM POSITION GENERIC ITEM B-24 CONTAINMENT FUF.3"3 Plant:

Unit No.:

Date:

Docket No.:

Licensee:

Licensee Response dated:

' Licensee.'s Comitnent:

(ifnone,sostate)

Item 1:

Item 2.a:

Item 2.b:

i Proposed NRC Staff Action:

(show expected date)

(1)

Issue Confimatory Letter:

(2)

Issue Show Cause Order:

(3)

Other:

Concurrence:

(1) Project Manager (2)

Branch Chief (3)

Ed Reeves (4) Assistant Director O

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6 PRELIMItiARY E.'ALUATIO?F INTERIM POSITIO!i GENERIC ITEM B-24 C0:iTAIfiMENT PURGIfiG Plant:

Unit No.:

- Date:

Docket No.:

Licensee:

Licensee Response dated:

Licensee's Comitment:

(if none, so state)

Item 1:

Item 2.a:

i Item 2.b:

i i

Proposed NRC Staff Action:

(Show expected date) 1 (1)

Issue, Confirmatory Letter:

(2)

Issue Show Cause Order:

(3)

Other:

Concurrence:

(1) Project Manager (2)

Branch Chief l

(3)

Ed Reeves-(4) Assistant Director i

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Mr.i..O.Mayer Northern States Power Company January 9,1980 cc: Gerald Charnoff, Esquire Shaw, Pittman, Potts and Trowbridge 1800 M Street, N.W.

Washington, D. C.

20036 Ms. Terry Hoffman Executive Director Minnesota Pollution Control Agency 1935 W. County Road B2 Roseville, Minnesota 55113 The Environmental Conservation Library Minneapolis Public Library 300 Nicollet Mall Minneapolis, Minnesota 55401 Mr. F. P. Tierney, Plant Manager Prairie Island Nuclear Generating Plant Northern States Power Company Route 2 Welch, Minnesota 55089 Joclyn F Olson, Esquire Special Assistant Attorney General Minnesota Pollution Control Agency 1935 W. County Road B2 Roseville, Minnesota 55113 Robert L. Nybo, Jr., Chairman Minnesota-Wisconsin Boundary Area Commission 619 Second Street Hudson, Wisconsin 54016 C1arence D. Fierabend U. S. Nuclear Regulatory Commission P. O. Box 374 Red Wing, Minnesota 55066

s REOUEST FOR ADDITXONAL INFORMATION FOR CONTAINMENT PURGE SYSTEM AND CONTAINMENT VEINTING SYSTEM FOR PRAIRIE ISLAND UNITS 1 & 2 DOCKET NOS. 50-282/306

- 1.

With the eiception of the containment ventilation isolation (CVI) system,- the docketed information as to the design of Engineered Safety Features (ESF) does not adequately address the following areas.

Please discuss how your ESF design conforms with each:

1 - The overriding

• of one type of safety actuation signal (e.g.,

radiation)_ should not cause the blocking of any other type of safety actuation signal (e.g., pressure).to the isolation valves.-

2 - Sufficient physical features (e.g., key lock switches) should be provided to facilitate adequace administrative controls.

3 - The system-level annunciation of the overridden status should be ornvided for the containment isolation system and for every safety system impacted when an override is active.

? - Diverse signals should be provided tc._ initiate -isolation of the containment ventilation system. Specifically, containment high radiation, safety injection actuation,,and containment hign pressure should automatically initiate Contaimnent Ventilation Isolation (CVI).

5 - The instrumentation and control systems provided to-tdttiate -

ESF should be designed and qualified as safety-grade equipment.

6 - The overriding or resetting

• of the isolation actuation signal should not cause the automatic motion of any ESF valve.

2.

Provide the process and instrumentation (P&ID) and schematic crawings fer your purge and vent system and control room heating, ventilation and air conditioning system.

3.

With regard to Criterion 4 of question 1 above, justify not providing for,, containment ventilation isolation on high containment pressure.

4.

With regard to Criterion 5 of question 1 above, please indicate if tne radiation monitors that initiate CVI are Class lE or not.

If tney are not justify their use for a required safety function.

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'Ine Tolicwing cefini:1ons are given for clarity of use in :nis issue:

l Ove rice - tne signal is still present, and it is blocked in order to perf:rm a function contrary to tne signal; Reset - the signal nas come i

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- anc ;:ne, and the circuit is being cleared to return to tne normal condition.

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MSP NORTHERN 5TATES POWER COMPANY M I N N S A PO L.l S. MI N N E SCTA 3 5409 March 17, 19 80 Director of Nuclear Reactor Regulation U S Nuclear Regulatory Commission Washington,'DC 20555 PRAIRIE ISLAND NUCLEAR GENERATING PLANT Docket Nos. 50-282 License Nos. Di'R-42 50-306 DPR-60 Additional Information Concerning Contairunent Purge and Vent System In a letter dated January 9,1980 from A Schwencer, Chief, Operating Reactors Branch #1, Division of Operating Reactors, USNRC, we' were asked to supply additional information related to the NRC Staff's ongoing review of problems associated with containment venting and purging.

Information requested in the enclosure to Mr Schwencer's letter is contained in Enclo-sure (1).

Enclosure (2) contains a comparison of the Prairie Island containznent purge and vent system design to NRC Branch Technical Position CSB 6-4.

This comparison was requested during a telephone conversation with Mr M Grotenhuis,

Project Manager, Operating Reactors Branch #1, USNRC.

Please contact us if you have any questions related to the information we have provided.

h.

L 0 Mayer, PE Manager of Nuclear Support Services f

LOM/DMM/jh I

cc J G Keppler 4

G Charnoff ff(T Enclosures i

DUPLICATE DOCUMENT Entire document previously entered into system under:

ANO TdD3 AJDffh No. of pages:

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