ML20053D261
| ML20053D261 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 06/01/1982 |
| From: | Emch R, Lantz E Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20053D256 | List: |
| References | |
| NUDOCS 8206040240 | |
| Download: ML20053D261 (3) | |
Text
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NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of CONSUMERS POWER COMPANY Docket No. 50-155
)(Spent Fuel Pool Modification)
(Big Rock Point Plant)
)
TESTIMONY OF EDWARD LANTZ AND RICHARD L. EMCH CONCERNING LICENSING BOARD QUESTIONS DATED MAY 13, 1982 Q.
Please state your names and your positions with the Nuclear Regulatory Commission.
A.
My name is Edward Lantz.
I am a Senior Reactor Engineer in the Reactor Systems Branch, Division of Systems Integration, United States Nuclear Regulatory Comissicr., Washington, D.C. 20555.
My name is Richard L. Emch.
I am employed as a Project Manager in the Division of Licensing, Office of Nuclear Reactor Regulation, Nuclear Regulatory Commission, Washington, D.C. 20555.
Q.
What is the scope of your testimony?
A.
This testimony addresses the three questions posed by the Licensing l
Board in its Memorandum dated May 13, 1982. The questions and our responses follow:
l (1) Is there anything in the geometry of the fuel pool, fuel elements, or spent fuel storage racks that could substantially alter natural water convection.
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No, there is nothing in the proposed geometry of the fuel pool, fuel elements, or spent fuel storage racks that could l
substantially alter natural water convection currents.
(2)
Is there a credible scenario, during a TMI-type accident or during more normal operating conditions, in which insulation or other debris could fall into the fuel pool and subtantially alter natural water convection currents?
There are credible accident scenarios whereby debris such as tools, coveralls, and other lightweight equipment could fall inot the pool. These scenarios, while credible, are still quite unlikely. However, because of the open rack 6 sign, there is no credible scenario which would result in significant blockage of water flow through the racks. The small amounts of blockage which are credible, but unlikely, would not substantially alter natural water convection currents.
(3)
If questions 1 or 2 are answered affirmatively, what are the implications of the affirmative answers for K,ff?
Any impediment to natural circulation will lead to a higher temperature in the spent fuel pool-Hypothetically, this could cause regions of local boiling in the spent fuel pool.
As long as the impediment is to the natural circulation flow
( t through the spent fuel assemblies themselves the K,ff in the modified pool will not go above 0.95. As I previously testified (Testimony of Edward Lantz submitted May 10, 1982, lines 117-121) K,ff could reach a maximum of 0.95 at a water temperature of 212 F with 1% void due to steam bubbles formed by boiling.
Increasing or decreasing the boiling temperature of the water above or below this point will reduce K because eff the water density will no longer be optimum.
If there were some way an impediment could stop the natural circulation flow through the intestitial regions without stopping it from going through the fuel assemblies, the maximum K
could be higher. However, with this open rack design this eff would be an unrealistic hypothesis.
.