ML17326A572
| ML17326A572 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 02/25/1980 |
| From: | Schwencer A Office of Nuclear Reactor Regulation |
| To: | Dolan J INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG |
| References | |
| NUDOCS 8003130043 | |
| Download: ML17326A572 (8) | |
Text
fEBRUARY 3 5 580 Docket Nos.
50-315 and 50-316 ftr. John Dolan, Vice President Indi,ana and Michigan Electric Coryany Post Office Box 18 Bowling Green Station Nevi York, New York 10004
Dear i'ir. Dolan:
During the last several years, data have begun to indicate that the fission gas release rate from LWR fuel pellets is increased (enhanced) with burnup.
Many of the current fuel performance analyses do not consider the impact of burnup-enhanced release on safety.
By letters dated November 23, 1976, the NRC staff requested all LWR licensees to assess the higher fission gas release for fuel burnups above 20,000 Megawatt-day per metric ton (NRD/t).
- Also, by NRC staff letter dated January 18, 1978, all U. S.
LHR fuel suppliers were requested to revise their fuel performance analyses to include the enhance-ment of fission gas release at higher burnups.
E All responses to the November 23, ]976 letters have been reviewed.
He have concluded that no immediate licensing action is required for operating reactors.
This conclusion is valid for typical reported LNR fuel bundle and batch burnups.
Any extension of these burnups or other'actors which significantly affect fission gas release, LOCA PCT or fuel rod internal pressure is outside the scope of the c.onclusion.,
Aestinghouse was. the only fuel s0pplier calculating that the increased release would cause internal fuel rod pressure to exceed coolant system pressure.
The staff has approved revised design criteria which allow internal rod pressures, greater than system pressure.
The staff is also completing the review of a ltestinghouse.revised fuel performance code.
The staff, in evaluating reloads, has been requesting licensees using Westinghouse fuel to quantify the burnup when the nevily approved design criteria will be violated.
In the reloads evaluated thus far, there appears to.be significant burnup margin to the newly approved design criteria to compensate for modifications which'may result from the staff review of the hlestinghouse revised fuel performance code.
~
'he.
responses concerning Combustion Engineering (CE} and Exxon PWR fuel bundles demonstrated that neither was there an adverse effect on ECCS evaluations nor did the internal fuel rod pressure exceed system pressure.
Therefore~gyjyedipte licensing action is necessary on CE or Exxon fueled Pt(Rs.
OTI ICC~
OVRHAMCW DATR9N KRC PORM 318 (9-76) NRCM 0240
- U O OOVORNMCNT TNINTINO ONPICCI I ~ T ~
24$
TIS
0 0
ti pl QX' s
YRAUR037 q ~
P t"
\\
a P
ldll I gl /f'
Nr. Oohn Dolan 0
Inasmuch as y'ou and/or the staff wil1 be evaluating all future reloads against fuel vendors'evised fuel performance codes which prOvide for increase in fission gas release at higher burnups, we consider this a satisfactory resolution of this concern.
S incerely,
. Original Signef SN r
cc:
See.next page A. Schwencer, Chief Operati'ng Reactors Branch
/)1 Division'f Operating Reactors
...DOR..
81.;C Schwe cer:pa
, 2/ggl80 OffICED DURNAML'~
DATE&
SEC EORM% %IS (976) NRCM 0240 I
j4 V 0 OOVORNMONT PRINTINO OffICEI 1000 0 ~ 0 0 ~ 0
~
, j:qw%t
~;@ 59AQf8 feoighQ.
II 1
I
~p,8 PECy Wp
+
0 y 0<
tp +e*w+
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 FKSRUAIIY 3 5 ~
Docket Nos.
50-315 and 50-316 Mr. John Dolan, Vice President Indiana and Michigan Electric Company Post Office Box 18 Bowling Green Station New York, New York 10004
Dear Mr. Dolan:
During the last several years, data have begun to indicate that the fission gas release rate from LWR fuel pellets is increased (enhanced) with burnup.
Many of the current fuel performance analyses do not consider the impact of burnup-enhanced release on safety.
By letters dated November 23, 1976, the NRC staff requested all LWR licensees to assess the higher fission gas release for fuel burnups above 20,000 Megawatt-day per metric ton (MWD/t).
- Also, by NRC staff letter dated January 18, 1978, all U. S.
LWR fuel suppliers were requested to revise their fuel performance analyses to include the enhance-ment of fission gas release at higher burnups.
All responses to the November 23, 1976 letters have been reviewed.
We have concluded that no immediate licensing action is required for operating reactors.
This conclusion is valid for typical reported LWR fuel bundle and batch burnups.
Any extension of these burnups or other factors which significantly affect fission gas
Westinghouse was the only fuel supplier calculating that the increased release would cause internal fuel rod pressure to exceed coolant system pressure.
The staff has approved revised design criteria which allow internal rod pressures greater than system pressure.
The staff is also completing the review of a Westinghouse revised fuel performance code.
The staff, in evaluating reloads, has been requesting licensees using Westinghouse fuel to quantify the burnup when the newly approved design criteria will be violated.
In the reloads evaluated thus far, there appears to be significant burnup margin to the newly approved design criteria to compensate for modifications which may result from the staff review of the Westinghouse revised fuel performance code.
The responses concerning Combustion Engineering (CE) and Exxon PWR fuel bundles demonstrated that neither was there an adverse effect on ECCS evaluations nor did the internal fuel rod pressure exceed system pressure.
Therefore, no immediate licensing action is necessary on CE or Exxon fueled PWRs.
Mr. John Dolan FEBRUARY 25 Inasmuch as you and/or the staff will be evaluating all future reloads against fuel vendors'evised fuel performance codes which provide for increase in fission gas release at higher burnups, we consider this a satisfactory resolution of this concern.
Sincerely
'g~c8<
A. Schwencer, Chief Operating Reactors Branch gl Division of Operating Reactors cc:
See next page
Mr. John Dolan Indi ana and Michigan El ectri c Company FEBRUARy 2 $
cc:
Mr. Robert W. Jurgensen Chief Nucl ear Engineer American E 1 ectri c Power Service Corporation 2 Broadway New York, New York 10004 Gerald Charnoff, Esquire Shaw, Pittman, Potts and Trowbridge 1800 M Street, N.W.
D.
C.
20036 Citizens for a Better Environment 59 East Van Buren Street Chicago, Illinois 60605 Maude Preston Palenske Memorial Library 500 Market Street St. Joseph, Michigan 49085 Mr. D. Shaller, Plant Manager Donald C.
Cook Nuclear Plant P. 0.
Box 458 Bridgman, Michigan 49106 Mr. Robert Masse Donald C.
Cook Nuclear Plant P. 0.
Box 458 Bridgman, Michigan 49106
8