ML20079E335
| ML20079E335 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 01/09/1984 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | Adensam A Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TASK-2.B.3, TASK-TM NUDOCS 8401170250 | |
| Download: ML20079E335 (2) | |
Text
w TENNESSEE VALLEY AUTHORITY CH ATTANOOGA. TENNESSEE 374o1 400 Chestnut Street Tower II January 9, 1984 Director of Nuclear Reactor Regulation Attention:
Ms. E. Adensam, Chief Licensing Branch No. 4 Division of Licensing U.S. Nuclear Regulatory Commission Washington, D.C.
20555
Dear Ms. Adensam:
In the Matter of
)
Docket No.
50-327 Tennessee Valley Authority
)
50-328 By my November 23, 1983 letter to you, we requested NRC approval of a proposed license amendment for the Sequoyah Nuclear Plant, units 1 and 2.
The proposed license amendment would allow completion of the codification associated with Postaccident Sampling (PAS) in order to comply with the operating license conditions, 2.C.(23).F for unit 1 and 2.C.(16).g for unit 2 and the requirements of Item II.B.3 of NUREG-0737. The details of the design and compliance with the design criteria of NUREG-0737 were provided in the November 23, 1983 letter. The justification for approval of the proposed license amendment, along with the significant hazards consideration determination pursuant to 10 CFR 50.92, was provided by my December 21, 1983 letter to you.
Enclosed is a revised response to criterion 11.B that was previously submitted to you by the November 23, 1983 letter.
If you have any questions concerning this matter, please get in touch with Jerry Wills at FTS 858-2683 Very truly yours, TENNESSEE VALLEY AUTHORITY 8401170250 840109 PDR ADOCK 05000327 p
PDR IV\\,
L. M. Mills, nager Nuclear Licensing Sworn 30 nd subsgrsbed before me th a
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My Commission Expires Y/f/ f()b NotafpPublic
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Enclosure cc:
U.S. Nuclear Regulatory Commission (Enclosure) g[
Region II Attn:
Mr. James P. O'Reilly Administrator
,jf 101 Marietta Street, NW, Suite 2900
[
Atlanta, Georgia 30303 1'983-TVA SOTH ANNIVERSARY An Equal Opportunity Employer
ENCLOSURE E
REVISED RESPONSE TO CRITERION 11.3 POSTACCIDENT SAMPLING NUREG-0737, ITE:4 II.B.3 SEQUOYAH NUCLEAR PLANT s
Criterion 11.B The ventilation exhaust from the sampling station should be filtered with charcoal adsorbers and high-efficiency particulate air (HEPA) filters.
Response
During normal plant operation, ventilation air is supplied to the PASF via the auxiliary building general ventilation system and an auxiliary supply fan. Exhaust air is ducted directly to the Auxiliary Building general ventilation system.
During postaccident conditions or sampling operations, the normal supply and exhaust systems are isolated, and ventilation air is taken directly from the outside at a point on the roof of the unit 1 additional equipment building. Both the unit 1 and unit 2 systems share this common intake. A supply ran provides air to the sampling side of the facility in response to a differential pressure controller. Air is drawn from both the sample and valve gallery areas by an exhaust fan. This air then passes through the postaccident g
sampling facility gas treatment system (PASF GTS) air cleanup unit and is then routed to the exhaust duct downstream of the Auxiliary Building gas treatment system (ABGTS) air cleanup unit. The sampling area is maintained at a positive pressure of 0.125 inch water gauge (WG) with respect to atmosphere while the valve gallery is kept at a negative pressure of -0.25 inch WG with respect to the sample side.
The radiological gas treatment subsystem, of the PASF GTS, consists of one HEPA/ Charcoal-type air cleanup unit located just upstream of the exhaust fan. Air supplied to the facility during postac'cident conditions or sampling operations is processed through the air cleanup unit before being discharged to the atmosphere.
The postaccident sampling facility environmental control system is not a nuclear safety-related system. However, it has redunda'nt isolation capability in all ductwork that interfaces with the ABGTS or penetrates the The isolation auxiliary building secondary containment enclosure (ABSCE).
valves and ductwork which interface with the AEGTS and ABSCE:are designed to seismic category 1 criteria. Also, the isolation valves are backed by Class 1E power. All remaining portions of the system are designed to seismic category I(L) criteria requirements.
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