ML19325E124
| ML19325E124 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 10/26/1989 |
| From: | Shelton D TOLEDO EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 1722, GL-86-10, NUDOCS 8911020025 | |
| Download: ML19325E124 (2) | |
Text
e O'
i a
m -
TOLEDO -
,i EDISON Ac ww wn m-v i
c 1
DONALD C. SHELTON,
I vu ww l
[419)249 2300 Docket Number'50-346 i
~>
License Number NPF-3 1,
1 Serial Number 1722 3
October 26, 1989 0
1 United States Nuclear Regulatory Commission i
Document Control Desk 1
LVashington, D.' C.20555
.J
[
Subjects Appendix R Pressurizer Level Exemption Request Withdrawal and Protection of Containment Equipment.
j Gentlemen:
^ Toledo. Edison requested three exemptions from the requirements of 10CFR50,
- Appendix R by ~ letter dated July 31, 1989 (Serial Number 1694)..One of'the
. exemption requests related to the lack of separation for the pressurizer level j
' instrumentation.
Subsequent to a verbal request.from the NRC for additional information on the pressurizer' level exemption request, Toledo Edison performed a valkdown and an additional engineering evaluation' to: assess the feasibility of: performing a modification to comply with the 10CFR50 Appendix R separation: requirements. Based upon the engineering'evoluation, Toledo Edison has' decided to withdraw the pressurizer-level exemption request.
Toledo Edison vill perform a modification to protect the electrical. components I
associated with the pressurizer level channels in accordance with the requirements of 10CFR50 Appendix R.
A 1/2 hour rated radiant energy shield vill be installed around the electrical components inside. containment including the transmitters, so that twenty feet of separation between the redundant instruments is attained. The steel instrument tubing for the pressurizer level transmitters does not meet the separation requirements but the' tubing would not be adversely affected by the heat from a postulated fire in'the area. The high pressure of the process fluid (approximately 2200 psi) combined with the lov fire loading in the area of the tubing ensures f
C.s pressurizer level instrument operability. Outside of the D-ring area, the
' routing of the tubing is at or below any cable trays and the tubing is 4
protected from above by an impingement shield along the length of the tubing run..Furthermore, there is negligible combustible loading below the instrument tubing elevation outside the D-ring area based on valkdown observhtions, thereby precluding an exposure fire. In the D-ring area, the tubing enters the D-ring through a common penetration and then runs to the side of the pressurizer nearest the penetration.
In the D-ring area, the j
THE TOLEDO EDISON COMPANY EDISON PLAZA 300 MADISON AVENUE TOLEDO, OHIO 43652
/'
0911020025 891026
+t EDR ADOCK 05000346
-W M6L
~
i DAcket Nu:ber 50-346 Lic ns] Numb;r NPP-3
'Sericl Nu ber 1722 i
,, 'a Page'2-i o
j'
~
combustible load consists of the oil in the Reactor Coolant Pumps (RCP) and hs the. cables for the pressurizer heaters.
The cables for the pressurizer
' heaters are on the opposite side of the pressurizer from where the tubing
~
attaches to the pressurizer. The Ipbe oil that would leak from the RCPs.is r
collected in the RCP motor oil drain-tank'which is spatially separated from and on.the opposite side of the D-ring from the pressurizer (i.e., over twenty t
feet from the pressurizer). The NRC has reviewed the design of the oil collection systems and, as documented in the letter dated August 20, 1984 (Log Number 1586), considers the system to be adequate to prever.t an exposure fire hazard.
i',
Based on the above information, Toledo Edison has concluded that the exemption previously requested is not required to demonstrate compliance with 10CFR50 Appendix R.
(
Additionally, the commitment to provide a one-hour radiant energy shield inside the containmer.t has been changed based upon NRC guidance.
In the responce to Question 43 in a letter dated May 27, 1987 (Serial 1361) Toledo Edison stated that the radiant energy shield protecting the Conteinment Air Cooler fans and the pressurizer level instruments-in the Containment and Annulus vould consist of a noncombustible material with a one-hour fire rating.
Based on the NRC guidance provided in Generic Letter 86-10, Toledo Edison vill provide a 1/2 hour fire rated radiant energy shield in lieu of the previously described one-hour fire rated radiant energy shield.
4
,1f you have any questions concerning this matter, please contact Mr. R. V. Schrauder, Nuclear Licensing Manager at (419) 249-2366.
Very trul yours, ll L k L %
DCV/ssg cc P. M. Pyron, DB-1 Senior Resident Inspector A. B. Davis, Regional Administrator, NRC Region III D. J. Kubicki, NRC/NRR Staff Reviewer T. V. Vambach, DB-1 NRC Senior Project Manager l
l i
-