ML18139A150

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Forwards Response to IE Bulletin 80-03 Re Charcoal Adsorber Cells.North Anna Charcoal Adsorber Cells in Use Do Not Have Potential for Loss of Charcoal.No Evidence of Degraded Cells Has Been Noted During Recharging at Surry
ML18139A150
Person / Time
Site: Surry, North Anna  Dominion icon.png
Issue date: 03/21/1980
From: Stallings C
VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To: James O'Reilly
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
IEB-80-03, IEB-80-3, NUDOCS 8004150164
Download: ML18139A150 (6)
v • d • e


Text

VIRGINIA ELECTRIC AND POWER COMPANY RICHHOND,VIBGINJ:A 23261 March 21, 1980 S-Mr. James P. O'Reilly, Director Serial No. 125/020680 ;~ ... --.-.

Office of Inspection and Enforcement PO/FHT:ug ~ ---~ '---'

U.S~ Nuclear Regulatory Commission Docket Nos: 50-280 ~ .- _-;.-)

Region II -28 J::> --*,

101 Marietta Street, Suite 3100 50-338 *: '. *._,

Atlanta, Georgia 30303 50-339 License Nos: DPR-32 DPR-37 CC NPF-4 CPPR-78

Dear Mr. O'Reilly:

IE Bulletin 80-03-Charcoal Adsorber Cells North Anna Power Station Units 1 and 2 Surry Power Station Units 1 and 2 i

In response to the subject bulletin, Virginia Electric and Power Company forwards the attached

  • responses for North Anna and Surry Power Stations.

If you have any .questions, or require additional information, please contact this office.

Very truly yours, cf.)!)?. yj'/aL4~~

C. M. Stallings Vice President-Power Supply and Production Operations cc: Director, Division of Fuel Facility and Materials Safety Inspection Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, D.C. 20555.

(j)

a* ATTACHMENT I

.. ,_,I e W PAGE I of 3 NORTH ANNA POWER STATION RESPONSE TO IE BULLETIN NO. 80-03

1. Determine if charcoal adsorber cells in use, or proposed for use, have the potential for a loss of charcoal incidental to handling, storage or use (as appropriate) *. Particular attention should be directed to exam-ination of a) rivet spacing resulting in separation of screen and cell housing and b) adsorber cell or filter housing deformation causing loss of charcoal and/or channeling. Either of these items could result in a degraded filtration system incapable of performing its intended function.

The preferred method of this determination is a visual inspection of the filter housing and adsorber cells as described in Section 5 of ANSI NSl0-1975.

  • If -this method is not feasible, state in the report -required by Paragraph 4' ,., *,

how the determination was made.

The charcoal adsorber cells in use and proposed for use do not have the potential for loss of charcoal. All of the cells use a welded construc-tion consisting of a series of spot welds with a maximum of one inch between welds. In addition to the close spacing of welds, the cell housing overlaps the screen to prevent separation and subsequent spillage. The construction of the cells by MSA and BARNABY-CHEENEY are similar and both incorporate the welded seams.

The adsorber cells are supported on angle brackets for nearly their entire depth and by four c:l amps on the front flange.. These supports preclude the possibility of adsorber cell deformation. Since the adsorber cells are held rigid, there is no potential for loss of charcoal or channeling due to cell deformation.

2. For ESF filtration systems, any identified defective cells shall be replaced and the operability of the system (after cell replacement) demonstrated by leak testing within 7 days. Preferred method of. leak testing is as described in Regulatory Guide 1.52 Rev. 2 and Section 12 *of ANSI NSl0-1975.

No defective cells were identified when representative filters were inspected.

3. For normal ventilation exhaust filtration systems which employ charcoal adsorber cells and for which radioactive removal efficiency has been assumed in determining compliance with the "as low as reasonably achievable" design
  • criteria of 10 CFR 50, Appendix I, any identified defective cells shall be replaced as soon as possible but at least within 30 days. After replacement, the system should be demonstrated operable by leak testing within an addi-tional 30 days. Preferred method of testing is as described in Regulatory Guide 1.140 and Section 12 of ANSI NSl0-1975.
    • North Anna Power Station does not use normal ventilation exhaust filtration systems which employ charcoal adsorber cells.

ATIACHMENT 1

-PAGE 2 of 3 e

4. Report in writing within 45 days of the date of this Bulletin the results of the detennination required by Paragraph 1. The report shall include the type of cells employed (manufacturer and cell design), system containing the cells, observed cell ~ondition (degradation/sagging) and~ discussion of visual inspection procedure and results.
  • Four different types of cells are employed. These cells are manufactured by two vendors.

Types of Cells:

A.) MSA - Standard and custom made cells standard cells - P/N 462137 with dimensions 24 11 x 6 1/4 11 x 30 11

  • The custom cells are the same construction as the P/N 462137 with the body length increased from 30 11 to 33 1/2 11
  • B.) BARNABY - CHEENEY - Standard &custom made cells standard cells have dimensions 23 3/4 11 x 611 x 30 11
  • The custom cells are the*

same construction as the standard cells with the body length increased from 30 11 to 33 1/2 11

  • C!) BARNABY - CHEENEY - Standard test cells. Dimensions 23 3/4" x 611 x 30 11
  • Each test cell contains 40 test canisters.

D.) BARNABY - CHEENEY - Custom made test cells. Dimensions 23 3/4" x 6" x 30 11

  • Similar to construction of standard test cell with only 6 test canisters.

The charcoal adsorbers are contained in the following three systems.

i) COMMON AUXILIARY BUILDING EXHAUST Mark No.: l-HV-FL-3A, B.

Cells: A, B &C ii) CONTROL &RELAY ROOM EMERGENCY SUPPLY Mark No.: l-HV-FL-8,9, 2-HV-FL-8,9 Cells: A &B iii) GASEOUS WASTE DISPOSAL Mark Na.: 1-GW-FL-lA, B Cells: A, B &D The charcoal adsarber cells inspected had no indication of degradation or sagging. The spacing of the spot welds (maximum of l") and the overlap of the cell housing with regard to the screen precludes the possibility of sagging.

At least one of each type of filter was inspected. The only cells utilized tha.t employ rivets are the MSA adsorbers. These cells use stainless pop

-rivets to attach the solid sheet metal cover on the bottom of the filter. These plates are used for replenishing the charcoal. The plates are narrow (less than two inches wide) and are made of 16 ga. stainless steel (304L). The thickness of these panels and the small dimensions provides sufficient rigidity to prevent loss of integrity.

. ' .... '-.~-

ATIACHMENT 1 e PAGE 3 of 3 The visual inspection was perfonned in compliance with ANSI* NSl0-1975, section 5. All cells inspected had no signs of degradation or the potential for degradation as described in IE Bulletin-~o. 80-03. *

~~~~-~

-J' '

Attachment 2

  • Page I of 2

_ SURRY POWER STATION RESPONSE TO IE BULLETIN NO. 80-03

1. Determine if charcoal adsorber cells in use, or proposed for use, have the potential for a loss of charcoal incidental to handling, storage or use (as appropriate). Particular attention should.be directed to exam-ination of a) rivet spacing resulting in separation of screen and cell housing and b) adsorber cell or filter housing deformation causing loss.

of charcoal and/or channeling. Either of these items could result in a degraded filtration system incapable of performing its intended fu~ction.

The preferred method of this determination is a visual inspection of the filter housing and adsorber cells as described in Section 5 of ANSI NSl0-1975. If this method is not feasible, state in the report required by Paragraph 4 how the determination was made.

The cells utilized in the ESF filtration systems are required to be leak tested by Section 4.12 of the Surry Technical Specifications. The test-ing required comprises a full leakage efficiency verification test and a charcoal efficiency removal test.. The .leakage verif-ication test is per-*

formed.under a station approved Periodic Test and is accomplished every_

12 to 18 months. As part of the test, a detailed visual inspection is performed on the cells and the surrounding structure and components.

All inspections and tests are performed in accordance with the applicable portions of Standard ANSI NSl0-1975 and comply with Regulatory Guide 1.52.

A review of previously completed tests has revealed that no degraded or damaged cells, or evidence thereof, has been discovered.

The charcoal efficiency removal test is performed every three years, and is used to verify charcoal adsorber efficiency. The results of both tests are used as a determinant for recharging the cells (charcoal replacement).

Although the cells in the Containment Local Iodine Filtration Fan Filter Banlcs are not tested or required to be tested as are the ESF system filters, they are also periodically recharged. No evidence of degraded cells has been noted_ during recharging to date.

2. For ESF filtration systems, any identified defective cells shall be re-placed and the operability of the system (after cell replacement) demonstrated by leak testing within 7 days. Preferred method of leak testing is as described in Regulatory Guide 1.52 Rev. 2 and Section 12 of ANSI NSl0-1975.

No defective cells have been identified during the regularly scheduled

_inspections.

3. For normal ventilation exhaust filtration systems which employ charcoal adsorber cells and for which radioactive removal efficiency has been assumed in determining compliance with the "as low as reasonably achievable"

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  • e e Attachement 2 Page 2 of 2 design criteria of 10 CFR 50, Appendix I, any identified defective cells shall be replaced as soon as possible but at least within 30 ~ays. After

.replacement, the system should be demonstrated operable by leak testing within an additional 30 days. Preferred method of testing is as described I.'

No defective cells have been identified.

4. Report in writing within 45 days of the date of this Bulletin the results of the determination required by Paragraph 1. The report shall include I: the type of cells employed (manufacturer and cell design), system contain-ing the cells, observed cell condition (degradation/sagging)* and a discussion of visual inspection procedure and results.

The adsorber cells in use at Surry are MSA Type II, fully rechargeable, partially riveted or screwed, gasket sealed adsorber trays.

  • They are utilized in the Main Auxiliary Building Filter Banks, the Control Room Filter Banks, the Relay Room Filter Banks and in the Containment Local Iodine Filtration Fan Filter Banks. The first three noted banks are ESF filtration systems.

Since surveillance and preventive.maintenance is maintained on the cells, and since no evidence of degraded or damaged cells has been discovered or indicated, the tests and inspections required by the.Bulletin will not be performed on the charcoal adsorber cells in use at Surry outside of the

,,., normally scheduled tests and inspections required by the Surry Technical Specifications *

.,

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