The short answer
Around UK sites that hold radioactive material above set amounts, councils plan for emergencies under the REPPIR 2019 regulations. The closest area is the Detailed Emergency Planning Zone (DEPZ), where sheltering, evacuation and stable iodine tablets are planned in advance; some sites also have a wider Outline Planning Zone (OPZ). The council must tell people in a DEPZ what to do, in print and online, at least every three years. Zone sizes differ by site: for example about 1.5 km at the Southampton nuclear berth and about 6.1 to 8 km at Sellafield. Only take iodine tablets supplied for this purpose and only when officials tell you. In any radiation emergency: go in, stay in, tune in.
Prints the checklist without the menus.
Do this now
- Find out if you're in a zone. Look for a leaflet, calendar or booklet from your council, or check its emergency planning page for a zone map.
- Sign up for any local warning system. Some sites run a free opt-in phone warning (Sellafield's covers landline, mobile, text and email).
- Keep the council's booklet with your emergency plan, and stick the emergency information line number by the phone.
- Learn the three words: go in, stay in, tune in (UKHSA).
- Have a battery or wind-up radio and a few days of water and food at home, because you may need to stay in for one to two days (UKHSA).
- If you were given iodine tablets, keep them at home and only take them when officials tell you to.
Free: the Alert Action Card
The first six steps for a nuclear or radiation alert, a missile or air attack alert, no water from the tap and a power cut, on one page for the fridge, plus a phone version you can open offline. Every step checked against GOV.UK, UKHSA and Be Ready on 3 November 2026. No sign-up needed.
Print card (A4 PDF, light) Phone version (PDF)
Want to hear when we update it?
Occasional emails when we update the card or publish new guides. Never daily. Unsubscribe any time. See our privacy notice.
What REPPIR is
The Radiation (Emergency Preparedness and Public Information) Regulations 2019, known as REPPIR, set the rules in Great Britain for planning for radiation emergencies. HSE says they cover sites that hold radioactive or fissile material above set amounts. That includes licensed nuclear sites, but can also include hospitals, universities, ports, airports and factories. They don't cover transport by road, rail, air or sea.
The two zones
| Zone | What it's for | What HSE says |
|---|---|---|
| Detailed Emergency Planning Zone (DEPZ) | The area nearest the site. Sheltering, evacuation and stable iodine tablets are planned in advance so they can start quickly | "DEPZs are about capabilities" |
| Outline Planning Zone (OPZ) | A wider area at some sites, for rare but more serious events. Less detailed planning | "OPZs are about information" |
Who decides: HSE says the local council sets the DEPZ, and an OPZ where needed, after reading the operator's consequences report and talking to the operator.
Testing: the Office for Nuclear Regulation says off-site emergency plans must include a test every three years.
Zone sizes differ by site
There is no single UK distance. Two examples from council documents we opened:
| Site | DEPZ | OPZ | Source |
|---|---|---|---|
| Sellafield (Cumbria) | about 6.1 to 8 km from the centre of the site | 50 km | Cumberland Council |
| Southampton nuclear berth (docks) | at least 1.5 km from the berth | 5 km | Southampton City Council |
Zones follow roads and natural boundaries, so they aren't perfect circles. Check your council's map rather than measuring a distance.
What the council must tell you
Under regulation 21 of REPPIR, the council, working with the site operator, must:
- make sure people in the DEPZ are made aware of the information, and given it where appropriate;
- make sure people in an OPZ have access to the information;
- publish it online and in print;
- review it at least every three years, and re-issue it at least every three years and after any change.
So if you live in a DEPZ and have never had anything, ask your council's emergency planning team.
How you'd be warned
It varies by site. Sellafield's July 2026 booklet says:
- the site siren (a foghorn sound) can sound, followed by the public telephone warning system;
- that system is opt-in and free: if you register, you get messages by landline, mobile, text or email;
- the siren is not used to sound the all clear; the end of an emergency is announced on local radio and the phone system;
- the siren is tested several times a year, with notice given locally;
- there's a pre-recorded Sellafield Emergency Information Line.
Emergency Alerts to mobile phones can be used for any life-threatening emergency: see what emergency alert did I just get?
What to do in a radiation emergency
UKHSA's advice:
- Go in: get indoors as soon as you can and stay there. Close doors and windows, keep away from outside walls.
- Turn off fans and air conditioning and close vents where you can. Sellafield's booklet adds: put out open fires and shut down multi-fuel stoves.
- Stay in until told it's safe. You may need to stay in for one to two days, longer if the release goes on.
- Tune in: follow the news, local radio and GOV.UK.
- Don't go to collect children from school if you've been told to stay in. Schools will keep them inside until it's safe to move.
- Bring outdoor pets in if they're near, but don't go looking for them once you're indoors.
- Don't evacuate unless told to. UKHSA says leaving shelter may increase your exposure.
- Follow food and water advice. UKHSA says milk or other foods may be banned after an emergency.
If you're away from home, UKHSA says shelter in the nearest building rather than travel home.
Iodine tablets: who gets them, and when
What they do: UKHSA says stable iodine speeds the removal of radioactive iodine from the body, cutting the dose to the thyroid. It protects the thyroid only, not the rest of the body.
When to take them: UKHSA says only when officially advised, and only the tablets provided for this purpose. It says a single dose protects for 24 hours. We don't give a dose here: follow the instructions with official tablets.
Who gets them: it depends on the site's plan. Examples:
- Southampton nuclear berth: the council's plan says tablets are provided to people within 1.5 km, downwind, delivered when an off-site nuclear emergency is declared.
- Sellafield: the July 2026 booklet we read doesn't mention iodine tablets. Its advice is to shelter, and evacuate if told.
So you can't assume everyone near any nuclear site gets tablets. Read your own council's information. Our post iodine tablets: should I buy them? explains why buying your own isn't recommended.
A nuclear site is not the same as a nuclear attack
REPPIR plans are for accidents at sites in Great Britain. They are not plans for a nuclear attack. For that, see nuclear attack warning: what to do and where is safer from nuclear attack?
Printable: if you live near a nuclear site
- I know if I'm in the DEPZ or OPZ (council map checked)
- I've signed up to the local warning system, if there is one
- Council booklet kept with our emergency plan
- Emergency information line number by the phone
- Battery or wind-up radio and spare batteries
- Water and food for 1 to 2 days indoors, or more (Be Ready asks for 3 days)
- Know how to turn off fans, ventilation and stoves
- School's emergency arrangements known; we won't collect children if told to stay in
- Pets can be brought in quickly
- Iodine tablets (if issued) kept at home; only taken when told
In an emergency
- Go in, close doors and windows, fans off
- Stay in until told it's safe
- Tune in: local radio, GOV.UK, the warning system
- Iodine tablets only if officials say so
- Follow food, water and evacuation advice
What to buy
About these links: plain links to ordinary retailer pages. We may earn from some links in future; we don't now. We haven’t tested these and we don’t rank them: they are examples that were in stock when we checked. Prices change. Check what you already own first. Full kit list
Battery or wind-up FM radio
Look for: FM (Be Ready asks for FM; DAB as well is fine). Both a crank and ordinary batteries, so you have two ways to power it.
Spare batteries
Look for: The sizes your torch, radio and alarms take. Check the date on the pack.
Torch or head torch, plus spare batteries
Look for: Runs on the same AA or AAA batteries as your other kit, so one spare pack covers everything. A head torch leaves both hands free.
- Alpkit Ionic 350 Lumen Head Torch · Alpkit · £15.99 (price on 1 November 2026) Shop
- Lifesystems Intensity 155 LED Head Torch · Lifesystems (UK brand store) · £19.99 (price on 1 November 2026) Shop
- Alpkit Kula 550 Lumen Head Torch · Alpkit · £19.99 (price on 1 November 2026) Shop
- Lifesystems Intensity 480 LED Hand Torch · Lifesystems (UK brand store) · £29.99 (price on 1 November 2026) Shop
- Dynamo Powered Wind-Up Pocket LED Torch · EVAQ8 · £3.60 (price on 1 November 2026) Shop
Bottled water
Look for: 3 litres per person per day for 3 days, for drinking. More for babies, pets and medical devices.
- Seven Oceans Emergency Drinking Water 0.5l (5-year shelf life) · EVAQ8 · £3.94 (price on 1 November 2026) Shop
Power bank
Look for: From a seller you know. Check the capacity (mAh) against your phone, and that you have the right cable for each phone. Keep it charged.
What we couldn't check
- We couldn't find one official list of every UK site with its DEPZ size. ONR's local arrangements page doesn't list them, so check your council.
- Several council and operator documents (Hinkley Point B in Somerset, Sizewell B in Suffolk, Hartlepool) were image-only PDFs, blocked or offline when we tried on 2 November 2026, so we haven't quoted them.
- REPPIR applies in Great Britain. Arrangements in Northern Ireland differ: check nidirect or your council.
- Zone sizes change when a site's consequences report is redone, for example when a power station closes.
Frequently asked questions
How do I know if I live in a nuclear emergency planning zone?
If you live in a Detailed Emergency Planning Zone, the law says your council must make you aware of what to do, so you should have had a leaflet, calendar or booklet. Councils also publish zone maps online. If you're not sure, check your council's emergency planning page or ring its emergency planning team.
What is a DEPZ?
A Detailed Emergency Planning Zone is the area around a site where the council plans in advance for sheltering, evacuation and stable iodine tablets, so they can start quickly if an emergency is declared. HSE says 'DEPZs are about capabilities'. Councils set the zone after reading the operator's consequences report.
What is an OPZ?
An Outline Planning Zone is a wider area some sites have, for rare but more serious events. HSE says 'OPZs are about information': planning is less detailed. At Sellafield the OPZ is 50 km; at the Southampton nuclear berth it is 5 km.
Who gets iodine tablets in the UK?
It depends on the site's plan. For example, Southampton City Council's plan says tablets are provided to people within 1.5 km, downwind, when an emergency is declared. UKHSA says take them only when officially advised, and only tablets provided for this purpose. We haven't given a dose because you must follow the instructions that come with official tablets.
Should I buy my own iodine tablets?
UKHSA's advice is to take only the tablets provided for this purpose, when officially told to. Our post on iodine tablets explains why buying your own isn't recommended.
How would I be warned?
It depends on the site. Sellafield's July 2026 booklet says the site siren sounds and a free opt-in public telephone warning system sends messages by landline, mobile, text or email. Emergency Alerts to mobile phones and local radio may also be used. Sign up for any local warning system your council offers.
Sources
We opened each page on the date shown. Official advice changes: if a source says something different now, follow the source.
- UKHSA (GOV.UK, updated 10 September 2024): What to do in a radiation emergency (read 2 November 2026)
- UKHSA (GOV.UK, updated 28 September 2026): Nuclear emergencies, information for the public (read 2 November 2026)
- HSE: Radiation (Emergency Preparedness and Public Information) Regulations 2019 (REPPIR) (read 2 November 2026)
- legislation.gov.uk: REPPIR 2019, regulation 21 (prior information to the public) (read 2 November 2026)
- Office for Nuclear Regulation: Local emergency arrangements (read 2 November 2026)
- Cumberland Council: What to do in an emergency at a nuclear site (Sellafield) (read 2 November 2026)
- Cumberland Council and Sellafield Ltd: What to do in an Emergency at Sellafield, July 2026 (PDF) (read 2 November 2026)
- Southampton City Council: Reactor emergency plan, public version (REPPIR 2019) (PDF) (read 2 November 2026)
Related guides
- Radiation emergency in the UK: what official advice says (go in, stay in, tune in)
- UK Emergency Alerts: a calm guide
- Emergency contacts list template (UK)
- Worried about war? How UK households can prepare — calmly
Free tools
We're an independent UK site, not the government. We check guides against official sources and link to them. In an emergency call 999.
More from the blog
Iodine tablets: who needs them, and why they won't help in most emergencies
What UKHSA, the US CDC and Norway say about potassium iodide: it protects only the thyroid, mainly after a nuclear reactor…
War & nuclearWhat to do if there's a nuclear or radiation warning in the UK
What UK official advice says to do if a nuclear or radiation warning comes: go in, stay in, tune in. Six steps, which room to…
War & nuclearWhere is safer from a nuclear attack in the UK? What official sources say, and what they don't
There is no official list of safer or riskier places in the UK for a nuclear attack. Here's why, what the government has…
War & nuclearFallout and food: is tap water and food in the cupboard safe?
What UKHSA and US guidance say about food and water after a radiation release or nuclear explosion: food and tap water indoors,…