A97031, Responds to NRC Re Violations Noted in Insp Repts 50-295/97-03 & 50-304/97-03.Corrective Actions:Revised Procedure PT-19,installed Mod to Isolate Vpc from Fhb When Wall Is Down & Enhanced 10CFR50.59 SE Process

Responds to NRC Re Violations Noted in Insp Repts 50-295/97-03 & 50-304/97-03.Corrective Actions:Revised Procedure PT-19,installed Mod to Isolate Vpc from Fhb When Wall Is Down & Enhanced 10CFR50.59 SE Process

ML20198F513
Person / Time
Site:	Zion  File:ZionSolutions icon.png
Issue date:	08/08/1997
From:	Mueller J COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
50-295-97-03, 50-295-97-3, 50-304-97-03, 50-304-97-3, ZRA97031, NUDOCS 9708130065
Download: ML20198F513 (8)

Text

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Zaon Gener.ning Ntation 101 Shiloh flouinant Xion,11. f m 42"V" Tel t4 N th20M 4 ZRA97031 August 8,1997 U. S. Nuclear Regulatory Commission Washington, D.C. 20555 Attention: Document Control Desk

Subject:

Commonwealth Edison Response to Apparent Violations in NRC Inspection Report Number 50-295/304-97003(DRS);

Zion Nuclear Power Statica Units I and 2; NRC Docket Numbers 50-295 and 50-304

Reference:

Letter to J. H. Mueller (Comed) from G. E. Grant (USNRC) dated July 9, 1997 NRC Inspection Report 50-295/97003(DRS),50-304/97003(DRS)

Gentlemer:

By letter dated July 9,1997, the NRC identified two related apparent violations which are being considered for escalated enforcement action in accordance with the " General /#

Statement of Policy and Procedure for NRC Enforcement Actions"(Enforcement Policy),

NUREG-1600. The first apparent violation involved Zion Station's identification that the [

removal of the block shield wall during the Unit 2 refueling outage caused a bypass of the normal ventilation system. This condition was discovered during a System Engineering -r walkdown of the fuel handling building ventilation system on November 7,1996. The /

related apparent violation involved the NRC identification that the Auxiliary Building / Fuel Building ventilation test was inadequate in that it did not alert the operators to the potential for the fuel building exhaust to bypass the charcoal filters in the event of a fuel handling accident. This letter and its attachments constitute Comed's reply to the apparent violations. By discussion with Mr. Mark Ring, Chief, Lead Engineers Branch, Region Ill, Comed agreed to provide this response in lieu of requesting a predecisional enforcement conference.

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ZRA97031 August 8,1997 Page 2 of 2 Attachment A to this letter provides the reasons for the violations, the corrective actions taken, and a statement of full compliance. Attachment B to this letter identi6es all commitments made by Zion Station in this response.

I affirm that the content of this transmittal is true and correct to the best of my knowledge, information and belief. In some instances these statements are not based on my personal knowledge, but on infonnation furnished by other Comed employees, contract employees and consultants. Such information has been reviewed in accordance with company practices, and I believe it to be correct.

Should you have any questions concerning this response, please contact Robert Godley of my staff at 847-746-2084 extension 2900.

Fjncerely, I .

I1 11. Mueller Site Vice President Zion Nuclear Station Subscribed and sworn to before me, a ' Notary Public in and for the State of dhd>ui, and County ofgh ,this M day of ,/,u e f ,19M. -

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cc: Regional Administrator, USNRC - Region III Senior Project Manager, USNRC - NRR Project Directorate III-2 Senior Resident Inspector, Zion Nuclear Station Office of Nuclear Facility Safety - IDNS Docuraent Control Desk j

- ATTACllMENT A to ZRA 97031 i Nge1of5 Response to Apparent Violations in Inspection Report 50-295(304)/97003tDRS)

VIOLATION: 50-295(304)/97003-01(DRS)

TS 3.13.2.A.] requires that during irradiatedfuel movement or crane operation with

) loads over irradiatedfuel in thefitel building, thefitel building exhaust system shall be operating with ventilationflow through the llEPA and charcoalfilters if any irradiated fuel is stored in the pool with less than 60 days time decay. During the recent Z2R14 refueling outage and all previous refiteling outages, approximately one-third of the air exhaustingfrom the FilB and containment b> passed the charcoalfilters, when the block shleid wall was removed tofacilitate moving equipment into containment.

Failure to assure that all FilB exhaust ventilation flow was through the llEPA and charcoalfilters during fuel handling activities associated with the Z2Rl4 refiteling outage is an apparent violation of TS 3.13.2.A. J.

ADMISSION OR DENIAL TO Tile VIOLATION

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Comed admits the violation.

REASON FOR Tile VIOLATION The reason for this violation is an original design error in that the Fuel liandling Building (F11B) ventilation system (charcoal filters) could be bypassed during refueling operations when the block wall is removed. The block wall between the containment hatch area and the FliB is designed for removal to facilitate movement oflarge equipment into and out of containment. Removal of this wall has been a standard practice during refueling outages. The nonnal ventilation supply for the area between the containment and the removable block wall is from the auxiliary building general area. The exhaust for this area is through the verticel pipe chase (VPC). However, when the wall is removed, the supply also comes from the FliB. Operating in this manner allows a significant portion of the FilB exhaust air to be routed through the VPC which is not normally vented ,

through charcoal filters. Technical Specification (TS) Amendment 43 (March 1979) allowed the containment equipment hatch to remain open during refueling operations.

The basis stated for removal of the hatch was radiation dose and outage duration savings.

As stated in the Safety Evaluation Report for Amendment 43 and the associated Technical Specifications,"The auxiliaty building ventilation system shall be operating in the charcoal filter mode whenever irradiated fuel is being handled." flowever, no documentation indicating recognition of the potential for a bypass path via the VPC, including 10 CFR 50.59 Safety Evaluations, could be found.

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- ATTACllMENT A to ZRA97031 Page 2 of 5 A contributing cause to this violation is management deficiency in that several opportunities existed for detection of this problem. The reviews focusing on F11B issues were too narrow. For example, the 10 CFR 50.59 Safety Evaluation prepared for a 1975 '

modification to the Unit I removable block wall considered the radiological shielding functions and seismic requirements for the wall; impact on FilB ventilation was not -

discussed. A similar Safety Evaluation was prepared for a 1984 modification to the Unit 2 removable block wall. Again, the review was limited to an evaluation of shielding and seismic issues related to the block wall. An engineering assessment perfonned in 1994 evaluated the potential for increased flow rate through the charcoal filters, incorrectly .

assuming that the air flow would be consistently from the VPC to the FilB.

CORRECTIVE ACTIONS TAKEN AND RESULTS ACHIEVED l-The station has revised PT-19, " Auxiliary Building / Fuel Building Ventilation Test," to assure that both the FilB and the VPC exhaust through charcoal filters Juring-fuel handling and crane movements over the fuel pool when the wall is down. This is accomplished by starting two Charcoal Booster Fans with their control switches placed in manual and failing the required dampers to their charcoal mode position with instrument air to the dampers isolated.

A modification to isolate the VPC from the FIIB when the wall is down was installed on Unit 1 prior to the core offload. This modification aligns the ventilation exhaust from the area between the containment and block wall through the FilB charcoal filters.

Zion Station has enhanced the 10 CFR 50.59 Safety Evaluation process by:

Implementing additional training for Safety Evaluation preparers on the requirement-to provide complete documentation of the thought process used during the performance of each safety evaluation. This training was completed during the fourth quarter 1996 continuing training sessions.

. - Implementing Nuclear Station Work Procedure (NSWP) A-04,"10 CFR 50.59 Safety Evaluation Process," that included an expanded set of Design issues Worksheets for consideration and use by 50.59 preparers and reviewers.

Establishing an Engineering Assurance Group (EAG), consisting of experienced engineering personnel, to review 10 CFR 50.59 Safety Evaluations to verify that the Safety Evaluations are complete and the conclusions are correct and sufficiently justified. The EAG will remain in place until sustained improvement in engineering product quality is demonstrated.

t ATTACilMENT A to ZRA97031 Page 3 of 5

. CORRECTIVE ACTIONS TAKEN TO AVOID FURTHER VIOLATIONS A modification identical to the Unit I modification described above will be installed to isolate the Unit 2 VPC from the FliB when the wall is down. This modification will be installed in refueling outage Z2R15.

l The station will conduct a review of the Auxiliary Building Ventilation System to l identify if any cther bypass leakage paths of the FHB exhaust exist. This review and any required Action Requests (AR) will be performed prior to fuel moves.

DATE WIIEN FULL COMPLIANCE WILL BE ACHIEVED l

1-Zion Station is currently in full compliance.

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A'ITACllMENT A to ZRA97031 4

PJge 4 of 5 4-VIOLATION: 50-295(304)/97003-02(DRS)

The inspector concluded that Surveillance Procedure PT-19 was not appropriate to the circumstances in that it never considered the efect ofremoval of the block wall on the results ofthe surveillance nor did the surveillance identify the bypass. Further, uhen the y surveillance wasfirst run, as required prior to movingfuel, the block wall was alreah

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down. As a result, there was no di[ference in the results ofthis test thanfrom any of the

. other surveillances which were performed every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> during the movement of irradiatedfuel. Therefore, performance ofthe surveillance never alerted the operators to the condition that approximately one-third of the air exhausting the FHB was bypassing the charcoalfilters.

Failure to have a surveillance test procedure that was appropriate to the circumstances for testing of the FHB ventilation is an apparent violation of10 CFR 50, Appendix B,

Criterion V.

ADMISSION OR DENIAL TO THE VIOLATION Comed admits the violation.

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! REASON FOR TIIE VIOLATION l The reason for this violation is that the surveillance requirement, (that the FHB be .

l verified at -1/4" WG with respect to atmosphere) was implemented literally by the-procedure without ensuring that the underlying intent of the technical specification surveillance requirement was met (that no unfiltered pathway from the FHB existed).

Procedure PT-19, " Auxiliary Building / Fuel Building Ventilation Test," allowed Zion Station to demonstrate literal compliance with the surveillance requirements of TS 3.13.2 (TS section 4.13.2). However, Zion Station failed to recognize the intent of TS 3.13.2; the charcoal filters in the ventilation train from the fuel building ensure that site boundary doses will be below 10 CFR 100 limits' during a postulated fuel drop accident. Since PT-19 did not include specific verification that all FHB exhaust pathways.were through the FHB ventilation system, the surveillance procedure was not capable of identifying.

potential bypass of the FIIB exhaust system.

t ATTACllMENT A to ZRA97031 Page 5 of 5 CORRECTIVE ACTIONS TAKEN AND RESULTS ACillEVEll The Improved Technical Specifications (ITS) include a specific surveillance to ensure that no ventilation flow path exists from the containment and FHB into the pipe tunnel when the wall is removed.

l CORRECTIVE ACTIONS TAKEN TO AVOID FURTIIER VIOLATIONS Surveillance Procedure PT-19, Auxiliary Building / Fuel Building Ventilation Test," will be revised to include verification that the exhaust will be through charcoal filter; This revision will be completed prior to fuel moves or crane operation with loads over irradiated fuel.

l Action Plan #13 of the Zion Recovery Plan describes actions required for ITS implementation. This plan includes specific steps to ensure that ITS surveillance requirements are incorporated into applicable procedures and to verify that the procedures are ready for implementation. ITS will be implemented prior to mode change of the first unit to be started.

Surveillance effectiveness improvements are addressed in item #10 of the Zion Recovery Plan. The Station will review a sample of surveillance procedures to verify that: the test requirements specified in the governing document are correctly tested by the procedure; the test provides clear, understandable acceptance criteria; and the modes of performance match the modes of applicability. Scheduled completion dates are as stated in the Zion Recovery Plan.

DATE WilEN FULL COMPLIANCE WILL BE ACIIIEVED Zion Station is currently in full compliance.

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.*+ ATTACllMENT 11 to ZRA97031 Page1ofI List of Comrnliments Identified in this Violation Response The following table identifies those actions commi:ted to by Comed in this document.

Any other actions discussed in this submittal represent intended or planned actions by Comed. They are described to the NRC for the NRC's information and are not regulatory commitments. Please notify Mr. Robert Godley, Zion Station Regulatory Assurance Manager, of any questions regarding this document or any associated regulatory commitments.

Commitment Committed Date or Outage A modification will be installed to isolate the Unit 2 VPC from the Z2R15 FilB when the wall is down. This modification will be installed in refueling outage Z2R15.

The station will conduct a review of the Auxiliary Building Prior to fuel moves.

Ventilation System to identify if any other bypass leakage paths of the FHB exhaust exist. This review and any required Action Requests (AR) will be performed prior to fuel moves.

Surveillance Procedure PT-19, " Auxiliary Building / Fuel Building Prior to fuel moves or Ventilation Test," will be revised to include verification that the cra .c operation with

! exhaust will be through charcoal filters. This revision will be loads over irradiated completed prior to fuel moves or crane operation wie loads over fuel, irradiated fuel.

Action Plan #13 of the Zion Recovery Plan

• scribes actions Prior to mode chang 7 required for ITS implementation. This plan includes specific steps of the first unit to be to ensure that ITS surveillance requirements are incorporated into started.

applicable procedures and to verify that the procedures are ready for implementation. ITS will be implemented prior to mode change of the first unit to be started.

Surveillance etTectiveness improvements are addressed in Item #10 None of the Zion Recovery Plan. The Station will review a sample of surveillance procedures to verify that: the test requirements specified in the governing document are correctly tested by the procedure; the test provides clear, understandable acceptance criteria; and the modes of performance match the modes of applicability. Scheduled completion dates are as stated in the Zion Recovery Plan.

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