ML20237G183
| ML20237G183 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood, 05000000 |
| Issue date: | 08/07/1987 |
| From: | Ainger K COMMONWEALTH EDISON CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| NUDOCS 8708130344 | |
| Download: ML20237G183 (2) | |
Text
[]> Comm:nwr!th Edison
-N
~
One Firs' National Plaza Chicago, Illinois
([ U Addrtss Reply to: Post Office E6i7BF N
Chicago, Illinois 60690 0767 L.
i August 7, 1987 i
i U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555
]
Subject:
Byron Station Unit 2 Braidwood Station Units 1 and 2 i
Startup Test program k
NJLC Docket Nos. 50-455, 50-456, & 50-457 l
I Reference (a): June 23, 1986 letter from K.A. Ainger to H.R. Denton Gentlemen:
Reference (a) proposed revisions to certain tests'in the startup test program for Byron Unit 2 and Braidwood. These caanges were based on the startup testing experience from Byron Unit 1.
One of the tests that was modified involved control rod drop measurements. Previously, this test had been performed at cold, no-flow, cold, full-flow, hot, no-flow, and hot, full-flow conditions in the reactor coolant system. The test was modified so rod drop measurements would only be performed at hot, full-flow conditions.
This request was made on the basis of a Westinghouse letter that stated "... rod drop time acceptance criteria based on FSAR and Tech Spec considerations are applicable only with the RCS at hot, full-flow conditions.
Based on past experience, we would anticipate that rod drop times at the other test conditions (i.e., hot, no-flow, cold, full-flow, and cold, no-flow) would fall under the hot, full-flow acceptance criteria, however this is not a design requirement."
The Westinghouse statement quoted above means that measured rod drop times at all other flow conditions should fall under the hot, full-flow acceptance criteria of less than or equal to 2.2 seconds.
This Westinghouse statement was slightly altered in reference (a) and presented as part of the basis for_ eliminating rod drop tests at other than the hot, full-flow conditions. ~ Reference (a) stated " Based on past experience, rod drop times at other test conditions fall under the hot, full-flow values." This incorre W y implies _that rod drop times at all other flow conditions fall under the measured value at the hot, full-flow condition.
8708130344 870007 PDR ADOCK 05000455
.P PDR g
"v i
US NRC August 7, 198*/
I The measured values of control rod drop times from Byron Unit 1 testing are as follows:
)
cold, no-flow 1.29 seconds Hot, no-flow 1.27 seconds cold, full-flow 1.58 seconds Hot, full-flow 1.46 seconds As expected, the condition involving the highest mass flow rate (i.e., cold,
)
full-flow) results in the longest drop time. However, at all flow conditions, the acceptance criteria for hot, full-flow (less than or equal to 2.2 seconds) is met.
The. Westinghouse statement that the acceptance criteria is only valid for the hot, full-flow condition, and that all other times will fall under this criteria, is the basis for our request that the rod drop time measurements need only be performed at hot, full-flow conditions. We believe the clarification of reference (a) presented above does not affect the conclusions reached by the NRC staff in their approval of our request to eliminate rod drop measurement tests at conditions other than hot, full-flow, please direct any questions regarding this matter to this office.
Very truly yours, K. n. Ainger Nuclear Licensing Administrator cc: NRC Region III Office Byron Resident Inspector Braidwood Resident Inspector 3429K a
I