- Date released
- 7 October 2020
- Request number
- 202009032
- Release of information under
- Freedom of Information Act 2000 (FOIA)
Information requested
- During an outage the airlock access doors are required/allowed to be both shut, both open or that either the internal or external door are allowed to be open based on the SOPs controlling the various stages of refuelling activity such as;
a) Stopping the reactor and filling the reactor vessel with boron moderator solution
b) Removing the reactor control head
c) Filling the reactor area/fuel transfer chute with boron moderator solution in preparation for fuel removal and reloading
d) Fuel removal
e) Fuel loading
f) Draining the reactor area/fuel transfer chute area in preparation for control head replacement
g) Control head replacement
h) Removal of boron moderator, refill with coolant
i) Operating conditions testing prior to criticality
j) Return to criticality and power generation - Please indicate for each separate stage of the outage covered by an SOP the status each of these two airlock doors from the point of view of;
a) The requirement of the SOP
b) The visible check at the airlock
c) The indicators on the control room panel
d) Any deviations that were noted and authorised, the reasons given
Please also provide the status of the maintenance door at each SOP stage above using the same reporting structure.
- Your indication from your FOI response is that “a door was left open after a 2016 refuelling outage”. Following completion of the final stage of testing discussed above please indicate;
a) Which airlock door was left open?
b) Was the status of the door indicated on the control room panel as being open or shut?
c) Was the door open when the reactor was being brought up to criticality and operating temperatures and pressures?
d) Had the door been shut by the time the reactor was at normal operating temperatures, pressures and critical nuclear reaction?
e) What types and number doors were considered as sufficient to provide secondary containment that are immediately beyond the airlock door that was left open?
f) What is the shortest route to loss of containment to the outside should a primary containment have been breached and how many doors and of what type are in that route?
g) How long was the door open for beyond the status described in both (c) and (d) above?
Information released
After careful consideration of all of the factors set out above, I can confirm that under Section 1 of the FOIA, we only hold the information related to question 3.a. of your request (3.a. Which airlock door was left open?). The roller shutter door at the top of the Equipment Access House (EAH) was found to be open.
With regards to all other questions (1, 2, 3.b. - 3.g.):
I confirm that under Section 1 of the FOIA, we do not hold the information related to the remainder of your request.
To put this into context, we do not hold copies of the operational documentation that would have the information you have requested within. If our inspectors need to view a SOP as part of their regulatory duties, they view them whilst on site when required where the information remains.
We would therefore recommend that you contact EDF Energy directly who may hold the information in scope of your request.
Their contact details are as follows:
Address:
EDF Energy
Sizewell B power station
Nr Leiston
Suffolk
IP16 4UR
Telephone:
+44 (0)1728 653653
Exemptions applied
N/A
PIT (Public Interest Test) if applicable
N/A