ML20148D847

Forwards Advanced Offgas Follow-up Rept, & Submits Response to Questions Contained in NRC

ML20148D847
Person / Time
Site:	Vermont Yankee
Issue date:	05/17/1997
From:	Reid D VERMONT YANKEE NUCLEAR POWER CORP.
To:	Cooper R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20148D852	List: ML20148D847 ML20148D858
References
BVY-96-66, NUDOCS 9706020133
Download: ML20148D847 (2)

Text

.. VERMONT YANKEE

(()a1I NUCLEAR POWER CORPORATION '[

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Ferry Road. Brattleboro, VT 05301-7002 ENGINEERING OFFICE i A 580 MAIN STREET BOLTON, MA 01740 (508)779-6711 May 17,1996 BW 96-66 U.S. Nuclear Regulatory Commission l Mr. Richard W. Cooper Director, Region i DMslon of Reactor Projects 475 Allendale Road King of Prussia, PA 19406-1415

Subject:

Reply to letter, R.W. Cooper, USNRC to D.A. Reid, W dated April 18,1996 As requested by the subject letter, we enclose a copy of the Advanced Offgas Follow-up Report, dated May 7,1996. No part of this report, or this letter, contains information that should be withheld from public disclosure under 10CFR 2.790.

The following is in response to the four questions contained in your letter:

1. "The basis for your confidence in the team leader's proficiency and independence to lead the assigned additional review."

The individual assigned as the Team Leader of the AOG Investigation Team is a degreed engineer with fourteen years of experience at Vermont Yankee. He has routinely participated in our Engineering Support Training Program, which includes plant system design and operation. Further, he has demonstrated the level of competence, independent judgement and familiarity with the faculty required for this assignment. The indMdual assigned as the Team Leader is one who regularly contributes appropriate and independent perspectives for senior management consideration.

Our confidence in the Team Leader also reflects confidence in the other members of the team, who have also demonstrated integrity, professionalism and a clear understanding of plant operations including the operation of the AOG system. The team was comprised of the team leader, our Quality Assurance Director, and our Engineering and Maintenance Training Supervisor who has training equivalent to that of a Senior Licensed Operator. A portion of this training required a detailed understanding of various plant system designs and performance including the AOG system.

All of the conclusions of the investigation Team were unanimous and, in the judgement of management clearly correct, in addition, the Investigation Team was assisted in its work by outside counsel who is independent of management, has approximately 20 years experience in nuclear regulatory matters and the Vermont Yankee plant, and who as a matter of course advises Individuals assigned a task such as this that such an assignment brings with it a special responsibility to probe and report independently.

Both of the AOG reports have been reviewed by our onsite Plant Operations Review Committee (PORC)

, and Nuclear Safety Audit Review Committee (NSARC) with no signific ut changes recommended nor 4

any safety concerns identified. D

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.. 'U.S. Nuciar R::gulatory Commission VERMONT YANKEE NUCLEAR POWER CORPORATION May 17,1996 i

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2. "An explanation as to why the initial answer given by the team leader at the VSNAP  :

stated that there was no AOG bypass."

The team leader indicates that he believed the question was referring to the capability of " bypassing" i the complete AOG system and the final radiation monitors at the plant stack.

Our subsequent review of the March 27 NENCP letter indicated the question was related to the ,

existence of an internal "startup bypass" that bypassed a portion of the system. However, elon if this i i

bypass is utilized, all gasses are still monitored for radiation within the AOG system as well as at the plant stack and the AOG system design ensures that the system would be isolated before any federal l or state radiation limits are reached.

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3. "An explanation as to why the diagram of the AOG system did not reflect the bypass capability?"

The sketch used at the VSNAP meeting was not intended to be a detailed system design drawing. In fact, it was prepared because we believed the engineering drawings we typically use were too detalled to appropriately communicate to the VSNAP. Therefore, a simple graphic depiction of the flow path of the AOG system was prepared. The sketch was intended to show those aspects of the AOG system that were identified by the Investigation Team to be relevant to the allegations made. The team specifically discussed the various bypass modes inherent to the design of the AOG system during their deliberations. Because the team had determined that the start-up bypass, as well as many other .;

features of the system, had no relevance to the allegations, they were not included in the drawing. l

4. " identify any periods of time since the last refueling outage when the bypass valves were open and why. If the bypass valves were open, confirm that any radiological releases were in compliance with the technical specifications."

The bypass valves have remained closed during the entire cycle of operation. The Investigation Team initially limited the time-frame of its investigation to the current cycle of operation based on the specifics of the allegation. Since the initial investigatim, we have also verified that the bypass valves have not been opened during normal operation since .ianuary 1984. Although the bypass lines exist for plant startup, there has been no need to utilize this design feature of the AOG system in the last several operating cycles.

If you have any further questions concerning this response, please let us know.

Very truly yours, Vermont Yankee Nuclear ower Corp.

2 Donald A. Reid Vice President, Operations