ML19308C315
| ML19308C315 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom, Crane  |
| Issue date: | 10/08/1976 |
| From: | Stello V Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19308C302 | List: |
| References | |
| TASK-TF, TASK-TMR NUDOCS 8001220708 | |
| Download: ML19308C315 (3) | |
Text
-
.O s
4 U881TED ST ATES NUCLEAR REGULATORY COMMISSION (O
j t
M 0 8 1976 wAsmuoTow, o. c. masas
)
%,..... p HEMORANDUM FOR:
Division Directors, Office of Nuclear Reactor Regulation Victor Stello, Jr., Director, Division of Operating FRUM:
Reactors Information Memorandum No.1
SUBJECT:
NON-N0BLE GAS FISSION PRODUCTS FUEL FAILURES - PEACH BOTTOM UNIT 2 NON-NOBLE GAS FISSION PRODUCTS l
Luring a recent fuel reload review, we evaluated the assumption of
(
neglecting fission products other than the noble gase.; in the calculation We concluded of fuel temperatures and internal pressures of fuel rods.
that infomation is not available to substantiate neglecting the effects Our current treatment of the volatilo of the volatile fission products.
fission products may provide a significantly low estimate of fuel-rod internal pressure and a significantly high estimate of the themal con-However, we believe that ductivity of the gas mixture in the fuel rod.
conservatisms existing in vendor fuels models and the requirement for ls normalization of these models to actual performance data provides m
l assurance that no immediate action needs to be taken.
l We have directed the Battelle Northwest Laborateries to further investigate the effects that volatile fission products in addition to
- (
Preliminary the noble gases have on fuel rod pressures and temperatures.
results are expected by November,1976. A determination of appropriate action will be made at that time.
FUEL FAILURES - PEACH BOTTOM UNIT 2 Nineteen bundles of 7x7R (Redesigned) fuel at Peach Bottom Unit 2 contain fuel rods that apparently failed as a result of a transient on January 13, This transient resulted in exposing the fuel to conditions de-l 1976.
parting from the General Electric Pre-Conditioning Interim Operating Management Reccmmendations. Ten of these bundles were to be non-destructively
+
examined.
On August 18, 1976, DDR staff and D. Houston, DSS, travelled In the ten to Peach Botton and studied the results of examinations.
bundles examined, fuel rods have been found to have failures as follows:
O 8001220 [N
r t
3 OCT 8 8 W6 A
1 t\\
y
- g Division Directors _e Ten fuel rods - failures in the fueled portion and cracks in the plenum region;
-ag Three fuel rods - failures in the fueled portion and crack:;
p i
near the upper end plugs; and Two fuel rods - failures in the fueled portion only.
The General Electric Company is continuing an investigation of this l
problem.
It has been observed that all the rods with failures in the l
plenum regior. also have failures in the fuel region.
It is believed that plenum cracking was not the initial failure in the rod. We believe that no new failure mechanism occurred.
It appears that these new con-sequences stem from a previously experienced f ailure mechanism, such as pellet-clad interaction or weld defects.
The 7x7R fuel incorporates a getter in the plenum region that may be contributing to the problem, w
)
The investigation underway by General Electric is expected to provide
{f' definitive information. We will continue to keep your staff infonned.
e
)p {
Victor Stello,
., Director Division of Operating Reactors Office of Nuclear Reactor Regulation i
D0R CONTACTS Fission Products R. Lobel M. Mendonca Feel Failures L. Olshan E. Verdery k
s n
1 O
f 4
I,
-g b
\\
I i
f OCT c e bis
't DISTRIBUTION B. Rusche E. Case Deputy Directors NRR Asst. Directors NRR D0R Branch Chiefs D0R Section i.eaders D. liouston R. Lobel M. Mendonca L. Olshan E. Verdery L. Nichols O
i k
N l
4 i
+
o
_-