MOX fuel pellet lot numbers with falsified data

An Investigation into the Falsification of Pellet Diameter Data in the MOX Demonstration Facility at the BNFL Sellafield Site and the Effect of this on the Safety of MOX Fuel in Use

Location	Lot	Assembly	Type of Falsification
In Japan	P783	005, 006	Type b - copying within spreadsheet, 47 exact cylinders
In Japan	P814	006, 007, 008	Copying from different part of spreadsheet for Lot P810
In Japan	P824	005, 006	Type a - copying, 308 matches with Lot P823
At Sellafield	P855	009, 011, 012	Type a - copying, 590 matches with Lot P853
"	P892	009, 011, 012	Type a - copying, 585 matches with Lot P881
"	P908	009, 010, 011	Type a - copying, 559 matches with Lot P898
"	P912	009, 010, 011	Type a - copying, 554 matches with Lot P900
"	P973	-	Type a - copying, 573 matches with Lot P965
"	P974	-	Type a - copying, 101 matches with Lot P973
"	P988	-	Type a - copying, 565 matches with Lot P970
"	P990	-	Type a - copying, 600 matches with Lot P971
"	P992	-	Type a - copying, 566 matches with Lot P985
"	P993	-	Type a - copying, 562 matches with Lot P990
"	P996	-	Type a - copying, 566 matches with Lot P994
"	P997	-	Type a - copying, 542 matches with Lot P991
"	P999	-	Type a - copying, 595 matches with Lot P972
"	P1001	-	Type a - copying, 592 matches with Lot P957
"	P1003	-	Manual Check - 14 identically sized pellets, see Note 1
"	P1007	-	Type a - copying, 548 matches with Lot P1000
"	P1008	-	Type a - copying, 539 matches with Lot P1000
"	P1009	-	Type a - copying, 535 matches with Lot P1002
"	P1015	-	Type a - copying, 541 matches with Lot P1011
"	P1018	-	Type a - copying, 558 matches with Lot P1011
"	P1021	-	Type a - copying, 537 matches with Lot P1019
"	P1023	-	Type a - copying, 530 matches with Lot P1021
"	P1024	-	Type a - copying, 511 matches with Lot P1019
"	P1026	-	Type a - copying, 522 matches with Lot P1025
"	P1027	-	Manual Check - 11 identically sized pellets, see Note 1
"	P1037	-	Manual Check - 12 identically sized pellets, see Note 1
"	P1039	-	Type b - copying within spreadsheet, including 23 identically sized pellets, see Note 1
"	P1046	-	Manual Check - 14 identically sized pellets, see Note 1

Note 1

Repeated line is the same across all five lots, P1003, P1027, P1037, P1039 and P1046. The diameter readings which are repeated in each of these Lots are 8.185, 8.187 and 8.189 mm.

Note 2

See Section 1.4, paragraph 9, for details of the types of falsification referred to above.

Fuel pellet quality characteristic

Shape, dimensions
- Outer diameter
- Length
- End profile
- End squareness
- Surface roughness
Surface condition
- Chips
- Cracks
- Other surface characteristics
- Cleanliness
Stoichiometry
- (U + Pu ) content
- Pu fissile content
- U 235 content
- Pu Isotopes
Impurities
Residual gas
Equivalent hydrogen content
Density
Thermal stability
Microstructure
- Grain size
- Pu distribution
- Pu solubility

Quality characteristics relevant to Fuel Rod

Fuel rod quality characteristic:

Rod identification
Components, fill gas identification
Cleanliness and freedom from damage of parts/assemblies
Dryness of cladding tubes welded at one end
Fuel column
- Length
- Fuel stack arrangement
Fuel weight
Moisture content in fuel rod
Fill gas composition and initial rod internal gas pressure
Leak tightness
Dimensional and Visual conformance
- Rod outer diameter
- Minimum clad wall thickness
- Rod length
- Rod straightness
- Girth weld diameter
Seal weld inspection
Rod surface
Rod decontamination
- Wipeable alpha contamination
- Fixed alpha contamination
Content of fissile material
Pellet gaps/pellet chipping within rod